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Shaved Legs = 15 watts?
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I feel like this whole thing should be written in pink because A) I'm being punked and am too stupid to know it or B) Jesse Thomas is being punked.

In the new Triathlete magazine, the hairy beast that is Jesse Thomas wrote that he did a shaved legs test at the "Win Tunnel" and they found he gained 15 watts by going shaved compared to full beast.

Am I missing something? It sure seems like I am.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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I've got nothing....I can't bash you for posting up yet another incredulous and completely irrelevant thread in the Tri forum instead of the lavender room because there is some validity here.

"I would definitely smell her seat after a century ride"
Rappstar wrote:
That might be the post of the year right there.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Don't forget the extra acceleration that you will gain from the reduction in weight.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Re: Shaved Legs = 15 watts? [shivermetimbers] [ In reply to ]
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shivermetimbers wrote:
I've got nothing....I can't bash you for posting up yet another incredulous and completely irrelevant thread in the Tri forum instead of the lavender room because there is some validity here.

I can go hide in a dark hole but I wasn't the one to write the article in a nationally published magazine. I felt like it was worth pointing out.

And I don't waste my time with the lavender room... I just waste my time here and classifieds.
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Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
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jackmott wrote:
Did he have REALLY hairy legs?

an old chet kyle test quoted 5 seconds per 40k, which is like 1 watt.

HAH! Yes, he talked about how hairy he was at length.

1 watt is understandable... they even posted the youtube video about going beard vs no beard and it came to 1 watt.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
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jackmott wrote:
if it was 15 grams of drag and he misremembered it would be consistent =)

Oh the joys of reading poorly written Triathlete since Inside Triathlon is gone.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Sorry, I don't know who Jesse Thomas is - is this guy?


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Re: Shaved Legs = 15 watts? [Midi-chlorian] [ In reply to ]
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No, this is Jesse


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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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To save 15W the legs would need to be "full sweater mode" with hair that didn't mat down much (even at 27mph) and increased FSA of the legs.

vs.

For those who don't want to shave, you can always do what Potts does and wear compression. Between the socks/sleeves and tri shorts, only the knees are uncovered.



ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)
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Re: Shaved Legs = 15 watts? [HowMuchLonger] [ In reply to ]
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HowMuchLonger wrote:
Don't forget the extra acceleration that you will gain from the reduction in weight.
yeah but it's revolving mass so that counts like 100x.
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Re: Shaved Legs = 15 watts? [Titanflexr] [ In reply to ]
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Compression calf and arm sleeves aren't legal anymore for non-wetsuit swims though...looks like he'll have to start shaving....

__________________________

I tweet!

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Re: Shaved Legs = 15 watts? [ZackCapets] [ In reply to ]
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He doesn't shave for Kona, which always seemed strange given his swimming background and the fact that he doesn't get to draft anyone during the swim.



ECMGN Therapy Silicon Valley:
Depression, Neurocognitive problems, Dementias (Testing and Evaluation), Trauma and PTSD, Traumatic Brain Injury (TBI)
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Re: Shaved Legs = 15 watts? [ollie3856] [ In reply to ]
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ollie3856 wrote:

HA! I literally just created a thread... just amazing for me since I never shaved before. Free speed baby!
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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i believe alphamantis has some data on this we published on slowtwitch, exactly 3 months ago.

Dan Empfield
aka Slowman
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Re: Shaved Legs = 15 watts? [Slowman] [ In reply to ]
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Slowman wrote:
i believe alphamantis has some data on this we published on slowtwitch, exactly 3 months ago.

HA!
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Re: Shaved Legs = 15 watts? [shivermetimbers] [ In reply to ]
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shivermetimbers wrote:
I've got nothing....I can't bash you for posting up yet another incredulous and completely irrelevant thread in the Tri forum instead of the lavender room because there is some validity here.


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Re: Shaved Legs = 15 watts? [ollie3856] [ In reply to ]
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ollie3856 wrote:

To reiterate the results. 50-80" seconds over 40k. Wow.

-------------------
Madison photographer Timothy Hughes | Instagram
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Re: Shaved Legs = 15 watts? [Timtek] [ In reply to ]
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Wow is right. That's like upgrading to a set of Zipp 404s, for free.
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Re: Shaved Legs = 15 watts? [Timtek] [ In reply to ]
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Timtek wrote:
ollie3856 wrote:



To reiterate the results. 50-80" seconds over 40k. Wow.

The economist in me would add the implicit cost to the time savings. That cost being: 1) Having shaved legs 2) Amount of time it takes to maintain shaved legs

_________________________________
The curious task of economics is to demonstrate to men how little they really know about what they imagine they can design.
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Re: Shaved Legs = 15 watts? [TheGupster] [ In reply to ]
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If someone is concerned with the maintenance time, just shave on race day.
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Re: Shaved Legs = 15 watts? [TheGupster] [ In reply to ]
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TheGupster wrote:
Timtek wrote:
ollie3856 wrote:



To reiterate the results. 50-80" seconds over 40k. Wow.

The economist in me would add the implicit cost to the time savings. That cost being: 1) Having shaved legs 2) Amount of time it takes to maintain shaved legs

Even taking that into account it would still be by far the most economical way to gain some speed.

______________________________________________
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Re: Shaved Legs = 15 watts? [Timtek] [ In reply to ]
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Timtek wrote:
ollie3856 wrote:


To reiterate the results. 50-80" seconds over 40k. Wow.

and honestly, we tested the hell out of this. Didn't believe it everytime and then the results kept showing up. 6 athletes up, consistent results regardless of hairiness or rider position. See below. And the 2nd graph is has total drag percentage of complete system on the Y axis...it's nuts how much this matters.






--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Pics of the pre-shaved condition? Just trying to put the Chewbacca scale in context :-)

http://bikeblather.blogspot.com/
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Re: Shaved Legs = 15 watts? [Timtek] [ In reply to ]
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Timtek wrote:
ollie3856 wrote:


To reiterate the results. 50-80" seconds over 40k. Wow.

Shit. Now I have to start shaving my legs. Goddammit.
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Hello MITaerobike and All,

How about some data on shaving arms and cutting off the pony tail?




Cheers,

Neal

+1 mph Faster
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Unbelievable. I had to look at this several times to make sure it wasn't a joke. As a guy with fairly hairy legs, I'm shaving for my next TT and triathlon. But I'm still showing up to the weekly roadie group ride with my hairy legs...


MITaerobike wrote:

and honestly, we tested the hell out of this. Didn't believe it everytime and then the results kept showing up. 6 athletes up, consistent results regardless of hairiness or rider position. See below. And the 2nd graph is has total drag percentage of complete system on the Y axis...it's nuts how much this matters.




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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Any idea if calf compression sleeves would have a similar effect to shaving when worn over hairy legs?

Or if compression sleeves are faster or slower then shaved legs?
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Re: Shaved Legs = 15 watts? [AG] [ In reply to ]
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Just shave, it looks 100 times better as well.

Endurance coach | Physiotherapist (primary care) | Bikefitter | Swede
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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I had always hoped this was bullshit because i don't want to shave my legs :(
Sad day
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Re: Shaved Legs = 15 watts? [mortysct] [ In reply to ]
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mortysct wrote:
Just shave, it looks 100 times better as well.

After you done this for a couple of decades how it looks is not so important.
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Re: Shaved Legs = 15 watts? [tom1111] [ In reply to ]
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Now I know why so many women beat me in races.
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Re: Shaved Legs = 15 watts? [elburrito99] [ In reply to ]
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I always tho u could save some time but 1min is f'ing HUGEEEEEE

The entire event (IM) is like "death by 1000 cuts" and the best race is minimizing all those cuts and losing less blood than the other guy. - Dev
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Re: Shaved Legs = 15 watts? [nealhe] [ In reply to ]
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In all seriousness, how about the arms? Does that make as big a difference?
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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MITaerobike wrote:
Timtek wrote:
ollie3856 wrote:


To reiterate the results. 50-80" seconds over 40k. Wow.


and honestly, we tested the hell out of this. Didn't believe it everytime and then the results kept showing up. 6 athletes up, consistent results regardless of hairiness or rider position. See below. And the 2nd graph is has total drag percentage of complete system on the Y axis...it's nuts how much this matters.

Thank you for publishing the testing like this! It's useful and well executed.

I mentioned this on the youtube vid, but if you guys know the aero penalty (if measurable) of wearing a watch on the bike it would be helpful to know.

-------------------
Madison photographer Timothy Hughes | Instagram
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Re: Shaved Legs = 15 watts? [fisherman76] [ In reply to ]
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fisherman76 wrote:
In all seriousness, how about the arms? Does that make as big a difference?


According to Jordan, yes.

Shaved Arms
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Re: Shaved Legs = 15 watts? [bwain] [ In reply to ]
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shaving EVERYTHING on race day to be on the safe side...

The entire event (IM) is like "death by 1000 cuts" and the best race is minimizing all those cuts and losing less blood than the other guy. - Dev
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Re: Shaved Legs = 15 watts? [nealhe] [ In reply to ]
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nealhe wrote:
Hello MITaerobike and All,

How about some data on shaving arms and cutting off the pony tail?




Cheers,

Neal

+1 mph Faster

Frontal pic would be very much appreciated.

Favorite Gear: Dimond | Cadex | Desoto Sport | Hoka One One
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Re: Shaved Legs = 15 watts? [GMAN19030] [ In reply to ]
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i hope she shaved the front...

The entire event (IM) is like "death by 1000 cuts" and the best race is minimizing all those cuts and losing less blood than the other guy. - Dev
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Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
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Looks like I need to add a new setting to the model.

-----------------------------------------------------------------
Founder: BestBikeSplit
Amazonian
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Re: Shaved Legs = 15 watts? [elburrito99] [ In reply to ]
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Insane. Absolutely insane to see the #'s... Shaving your legs is completely free speed... Nuts. I think my wife would divorce me.

-Alex

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Re: Shaved Legs = 15 watts? [bostonalex] [ In reply to ]
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I think I'll start doing this for races. Just like swim team, the drag in training is no big issue. Maybe even helps. Then shave as part of the big race ritual to get your game face on.

----------------------------------------------------------
Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com
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Re: Shaved Legs = 15 watts? [ollie3856] [ In reply to ]
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ollie3856 wrote:

If I cut myself as much as the guy in the video I would skip shaving.
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Re: Shaved Legs = 15 watts? [asad137] [ In reply to ]
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asad137 wrote:

Shit. Now I have to start shaving my legs. Goddammit.

These are my thoughts exactly. I've never shaved my legs. Even as a competitive swimmer in high school I could never bring myself to do it. I'm not a very hairy guy so there is no way I would gain 15 watts, but even if it's only 3-4 I can't really pass that up. I have spent a lot of money and trained my ass off for those kinds of gains...
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Re: Shaved Legs = 15 watts? [endosch2] [ In reply to ]
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endosch2 wrote:
Now I know why so many women beat me in races.
x2

Swim - Bike - Run the rest is just clothing changes.
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Re: Shaved Legs = 15 watts? [dkidwell] [ In reply to ]
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Our tester who saved 50 secs had tall socks, low shorts (just above the knee), and had thin thin hair over the knee and upper lower legs.

That was a massive difference. I can confidently say that those with light leg hair thinking this doesn't apply to them need to believe this is as big of a difference as it is.

Arms we aren't very far on testing. We need a lot of data for this - TT and road positions will be very different. There's likely a difference but not as much as legs.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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I am in a fetal position on the floor agonizing over all the TT's I lost by 5-10 seconds. And all the years I scoffed at all the conformist cyclists who made fun me for not shaving.
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Re: Shaved Legs = 15 watts? [dkidwell] [ In reply to ]
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dkidwell wrote:
These are my thoughts exactly. I've never shaved my legs. Even as a competitive swimmer in high school I could never bring myself to do it. I'm not a very hairy guy so there is no way I would gain 15 watts, but even if it's only 3-4 I can't really pass that up. I have spent a lot of money and trained my ass off for those kinds of gains...
Well, at least that's one thing you won't need to shave now. :)

-----
Two roads diverged in a wood, and I--
I took the one less traveled by,
Which is probably why I was registering 59.67mi as I rolled into T2.

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Re: Shaved Legs = 15 watts? [bostonalex] [ In reply to ]
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bostonalex wrote:
Insane. Absolutely insane to see the #'s... Shaving your legs is completely free speed... Nuts. I think my wife would divorce me.

I said to my wife ' hey hun, specialized have done a bit of wind tunnel testing, and whaddya know, shaving the legs saves over a minute in a 40km TT'.....i got the same response as you.. 'do that shit and we are getting divorced'.
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Please do whatever you need to do in order to fix the data that shows arm hair does not impact drag.

Between the legs, face, head and a little manscaping, I ain't got much left.

Chicago Cubs - 2016 WORLD SERIES Champions!!!!

"If ever the time should come, when vain and aspiring men shall possess the highest seats in government, our country will stand in need of its experienced patriots to prevent its ruin." - Samuel Adams
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Re: Shaved Legs = 15 watts? [trail] [ In reply to ]
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trail wrote:
I am in a fetal position on the floor agonizing over all the TT's I lost by 5-10 seconds. And all the years I scoffed at all the conformist cyclists who made fun me for not shaving.

You and me both. My wookie arse ended up 2nd in my AG by 6 seconds a couple weeks ago...
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Question for Mark Cote and Chris Yu:

Wind tunnels and razors have been available for a long time now. Why did it take so long for some one to do a controlled wind-tunnel test of this? What I'm saying is - I'm sure this has been tested before and (I'm assuming) the tests have shown that aero gains from shaving to be insignificant. Has everyone who has ever said, "shaved legs don't matter except for road rash" just been BS'ing all of these years?

Not trying to troll - I'm genuinely interested in your answer to this.
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:
Question for Mark Cote and Chris Yu:

Wind tunnels and razors have been available for a long time now. Why did it take so long for some one to do a controlled wind-tunnel test of this? What I'm saying is - I'm sure this has been tested before and (I'm assuming) the tests have shown that aero gains from shaving to be insignificant. Has everyone who has ever said, "shaved legs don't matter except for road rash" just been BS'ing all of these years?

Not trying to troll - I'm genuinely interested in your answer to this.

I do not think that assuming this testing has been performed before is a good assumption. Why would someone test this before? Why would a bike company test this, they would spend their expensive windtunnel time actually improving their product. Same with a wheel manufacturer, they would test wheels, not test shaved legs. Sure some people may have had a bit extra time and tried a one off, but then maybe would have looked at the results and assumed they messed up. It really takes someone to be able to this a bunch of times.

Now that specialized has a windtunnel, they can now do this sort of thing as advertising. They can show the consumer, "Hey, look at our capabilities! We are putting these same tools and knowledge into our bikes!".
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Re: Shaved Legs = 15 watts? [JayZ] [ In reply to ]
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For you full sasquatch wookiee types, can i take it this to mean that you're alright with the hairs poking out of your shorts all over your ass and around your junk?
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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I agree... Some pretty odd things have been tested in the tunnel... I just have a hard time thinking this never came up before as often as it's given as a reason to shave your legs.
Admittedly it could've been tested and the info just never got out, and repeatability is there (w/ multiple athletes) in what Spec has put out.

Glad I've always shaved nonetheless. (I always did it because of the cultural thing...)

My Blog - http://leegoocrap.blogspot.com
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Re: Shaved Legs = 15 watts? [chaparral] [ In reply to ]
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> They can show the consumer, "Hey, look at our capabilities! We are putting these same tools and knowledge into our bikes!".

It also shows that:

a) there will never cease to be amazingly counter-intuitive results from the wind tunnel

b) not everything can be easily replaced by computer modelling. Try a modelling a variety of leg hair in STAR CC+, etc. I bet it's not fun.
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Re: Shaved Legs = 15 watts? [chaparral] [ In reply to ]
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Why would someone test this before? Well at the beginning of the video one of them said that the shaved legs thing is one of the most frequent questions asked about aero, that's why.

Specialized is a bike / components company, and they just tested shaved vs. unshaved legs. You just answered your question "why would a bike company test this?" in your last sentence.

Wind tunnels have been around for a long, long time so I'm just wondering if there are any other studies / tests and if not, then why did it take so long. In fact you don't really need a wind tunnel to test this - people have been measuring the real-world effects of aero for quite a while outside of a wind tunnel using controlled roll down tests or riding around a track with a power meter. I even remember reading an experiment that Mark Cote did at Specialized using some Australian ProTour cyclist, a closed velodrome / track, and a power meter (I think it was to test effects of tri bike vs. road bike with aero bars, TT helmet vs aero helmet, and other stuff).

In short - since everyone has been debating this ad nauseum since the beginning of time, is this really the first test of shaved legs in a wind tunnel? If not - then how do the other studies compare?
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Re: Shaved Legs = 15 watts? [fisherman76] [ In reply to ]
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fisherman76 wrote:
For you full sasquatch wookiee types, can i take it this to mean that you're alright with the hairs poking out of your shorts all over your ass and around your junk?

no?
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Re: Shaved Legs = 15 watts? [trail] [ In reply to ]
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trail wrote:
b) not everything can be easily replaced by computer modelling. Try a modelling a variety of leg hair in STAR CC+, etc. I bet it's not fun.

Wait, you don't think that would be fun? Seems like a fun project to me.
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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What about going from very hairy and using an electric shaver to trim down but still having stubble and not doing the full shave. Thoughts.
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:

In short - since everyone has been debating this ad nauseum since the beginning of time, is this really the first test of shaved legs in a wind tunnel? If not - then how do the other studies compare?

Because people love to debate thing, but people are less likely to put the actual work to actually test it and also it is not like many people have the tools and knowledge to test it (powermeters for field testing have been less common until recently and using them for it takes some skill).

Just imagine you are a Cervelo engineer and you have a limited amount of windtunnel time, do you think your boss would rather have you spend that time testing changes to a new frame design or seeing if shaved legs saves any time? Let alone getting the multiple people to do that testing. Or if you are testing pro tour cyclists that already shave their legs and would not be racing with unshaved legs anyway, why spend time in the tunnel with the pros testing this, it makes more sense using that time to test positions and equipment.

I think the biggest reason it has not been tested is that nobody thought it would be this big of a result.
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Re: Shaved Legs = 15 watts? [chaparral] [ In reply to ]
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chaparral wrote:
aaronechang wrote:
Question for Mark Cote and Chris Yu:

Wind tunnels and razors have been available for a long time now. Why did it take so long for some one to do a controlled wind-tunnel test of this? What I'm saying is - I'm sure this has been tested before and (I'm assuming) the tests have shown that aero gains from shaving to be insignificant. Has everyone who has ever said, "shaved legs don't matter except for road rash" just been BS'ing all of these years?

Not trying to troll - I'm genuinely interested in your answer to this.


That's a great question. The only data I've ever seen was Chester Kyle's report from 1987 which called out a few seconds saved over 40km. A couple of things:

-(Almost) no one is going to rightfully spend the time or money renting time in someone else's wind tunnel to answer this question. We spent about 12 hours on this study (maybe a bit more with some evening sessions) and there's no way we would've spent the money at A2, UWAL, SDLSWT, etc to do this test. With flights and logistics, this would've been around a $15k test.

-I don't think anyone expected the results to be this crazy impactful. We didn't. We expected what Chet's report had said. Additionally, there are only a few shoe covers we've ever seen to work really well and no-one makes a good full body skinsuit today (i.e. see Nike running tracksuits from 2000 Olympics and onward) so the leg thing hadn't really been studied.

-We're doing this testing to finally answer the questions we've all had but haven't had a facility like this at our finger tips. It's what TomA has done with his RR testing, what Andy Coggan has done with his home wind tunnel on brakes, what Robert Chung has done with on road testing - it's getting some useful, general knowledge out to the world in as scientific but brief of a way we can. If these were all white papers, we wouldn't have time to do this but since video is an awesome medium we can get some of this data out there. We only spend a few days a month working on this. I promise we still do real work too.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Shaved Legs = 15 watts? [trail] [ In reply to ]
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trail wrote:
> They can show the consumer, "Hey, look at our capabilities! We are putting these same tools and knowledge into our bikes!".

It also shows that:

a) there will never cease to be amazingly counter-intuitive results from the wind tunnel

b) not everything can be easily replaced by computer modelling. Try a modelling a variety of leg hair in STAR CC+, etc. I bet it's not fun.

These are good points. Also, your the last point could easily have the words "computer modeling" replaced by "wind tunnel". The goal of all of this is to find free real-world speed, and the computer and wind tunnel are just simplistic models of the real world.

In Michael Hutchinson's book Faster, Chris Boardman talks about how computer modeling enabled British Cycling to calculate esoteric stuff and just let the computer sit there and crunch for hours overnight to find marginal gains in areas that no one would ever think of looking (shape of the front fork, for instance). Then they would actually test what the computer suggested with a real rider on a real bike. More often than not, the computer's suggestions did not ending up making any significant difference in the real world. But sometimes it did. And it was a lot easier to have a computer point them in the right direction than just randomly guess and try changing everything one piece at a time.

The wind tunnel is the same thing - results in the wind tunnel often do not match up with what you get in the real world. Boardman talked about how surrounding trees / foliage and buildings would often complicate things, especially when you're talking about things like dirty air caused by rotating wheels and churning legs.

A lot of wheel companies, I suspect, test their wheels in the wind tunnel by themselves (not on a real bike with a real rider pedaling). Which doesn't really have any applicability to how they will be used in real life. Same way a lot of tire companies test their tires on a steel drum (not on a real bike with a real rider pedaling).

Anyways I'm not trying to argumentative or simply trying to be a contrarian here. I'm by no means a professional aerodynamicist, I'm just interested in this topic and try to read as much as I can about it. That's why I'd like to hear what Mark and Chris have to say about this.
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Huge thanks to Specialized for doing this and letting us all know. My next bike will be a Specialized, such a great idea publishing these short videos.


MITaerobike wrote:
chaparral wrote:
aaronechang wrote:
Question for Mark Cote and Chris Yu:

Wind tunnels and razors have been available for a long time now. Why did it take so long for some one to do a controlled wind-tunnel test of this? What I'm saying is - I'm sure this has been tested before and (I'm assuming) the tests have shown that aero gains from shaving to be insignificant. Has everyone who has ever said, "shaved legs don't matter except for road rash" just been BS'ing all of these years?

Not trying to troll - I'm genuinely interested in your answer to this.


That's a great question. The only data I've ever seen was Chester Kyle's report from 1987 which called out a few seconds saved over 40km. A couple of things:

-(Almost) no one is going to rightfully spend the time or money renting time in someone else's wind tunnel to answer this question. We spent about 12 hours on this study (maybe a bit more with some evening sessions) and there's no way we would've spent the money at A2, UWAL, SDLSWT, etc to do this test. With flights and logistics, this would've been around a $15k test.

-I don't think anyone expected the results to be this crazy impactful. We didn't. We expected what Chet's report had said. Additionally, there are only a few shoe covers we've ever seen to work really well and no-one makes a good full body skinsuit today (i.e. see Nike running tracksuits from 2000 Olympics and onward) so the leg thing hadn't really been studied.

-We're doing this testing to finally answer the questions we've all had but haven't had a facility like this at our finger tips. It's what TomA has done with his RR testing, what Andy Coggan has done with his home wind tunnel on brakes, what Robert Chung has done with on road testing - it's getting some useful, general knowledge out to the world in as scientific but brief of a way we can. If these were all white papers, we wouldn't have time to do this but since video is an awesome medium we can get some of this data out there. We only spend a few days a month working on this. I promise we still do real work too.

Mark
Quote Reply
Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
Quote | Reply
I wouldn't entirely agree with this. Yes trees/foliage will change the wind speed you might have expected at ground level if you were modeling things, but generally if you take a rider with a wind tunnel measured CdA, have them do a time trial, run the power meter data through the equations of motion of cycling, you get results accurate within a few seconds.

Or, you can look at the TT results and compute the power the cyclist must have done and compare that to the measured power, and that is also very close, see: http://www.recumbents.com/...20road%20cycling.pdf

Given the numerous confounding factors, such as not having perfect data about ambient wind, power meters not being perfectly accurate, riders not holding their wind tunnel positions perfectly all the time, that modeled vs measured data is so close suggests a wind tunnel represents the real world very, very well.


aaronechang wrote:
The wind tunnel is the same thing - results in the wind tunnel often do not match up with what you get in the real world. Boardman talked about how surrounding trees / foliage and buildings would often complicate things, especially when you're talking about things like dirty air caused by rotating wheels and churning legs.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Quote Reply
Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
Quote | Reply
MITaerobike wrote:
That's a great question. The only data I've ever seen was Chester Kyle's report from 1987 which called out a few seconds saved over 40km. A couple of things:

-(Almost) no one is going to rightfully spend the time or money renting time in someone else's wind tunnel to answer this question. We spent about 12 hours on this study (maybe a bit more with some evening sessions) and there's no way we would've spent the money at A2, UWAL, SDLSWT, etc to do this test. With flights and logistics, this would've been around a $15k test.

-I don't think anyone expected the results to be this crazy impactful. We didn't. We expected what Chet's report had said. Additionally, there are only a few shoe covers we've ever seen to work really well and no-one makes a good full body skinsuit today (i.e. see Nike running tracksuits from 2000 Olympics and onward) so the leg thing hadn't really been studied.

-We're doing this testing to finally answer the questions we've all had but haven't had a facility like this at our finger tips. It's what TomA has done with his RR testing, what Andy Coggan has done with his home wind tunnel on brakes, what Robert Chung has done with on road testing - it's getting some useful, general knowledge out to the world in as scientific but brief of a way we can. If these were all white papers, we wouldn't have time to do this but since video is an awesome medium we can get some of this data out there. We only spend a few days a month working on this. I promise we still do real work too.

Mark

Thanks for the response - that's what I was looking for. A quick Google search does turn up lots of references to the Chester Kyle report (0.6% saved when shaving legs), but unfortunately I can't find any links to the study itself. So we can't really compare it with yours and discover why there was such a big discrepancy between the two studies.

I agree that wind tunnel testing is prohibitively expensive. A few years ago Bicycle Quarterly did a very comprehensive wind tunnel test, which they were able to rent out either for free or at heavily discounted rate (it was at a local university and one of their testers either worked there or had connections there, please don't quote me on that). They tested the effects of baggy clothing, loose cycling jersey, skintight jerseys, handlebar height, front vs rear panniers, front vs. rear fenders, pretty much anything you can think of. Except for shaved legs, since they assume that they were so insignificant as to not even merit testing.

So I guess the answer is - no one has tested this before because no one has thought it was worth testing.
Quote Reply
Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
Quote | Reply
did you look at just leaving a strip on the backside of the legs :) kinda like what some folks say to do to the trailing edge of forks
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:
Why would someone test this before? Well at the beginning of the video one of them said that the shaved legs thing is one of the most frequent questions asked about aero, that's why.

Specialized is a bike / components company, and they just tested shaved vs. unshaved legs. You just answered your question "why would a bike company test this?" in your last sentence.

Wind tunnels have been around for a long, long time so I'm just wondering if there are any other studies / tests and if not, then why did it take so long. In fact you don't really need a wind tunnel to test this - people have been measuring the real-world effects of aero for quite a while outside of a wind tunnel using controlled roll down tests or riding around a track with a power meter. I even remember reading an experiment that Mark Cote did at Specialized using some Australian ProTour cyclist, a closed velodrome / track, and a power meter (I think it was to test effects of tri bike vs. road bike with aero bars, TT helmet vs aero helmet, and other stuff).

In short - since everyone has been debating this ad nauseum since the beginning of time, is this really the first test of shaved legs in a wind tunnel? If not - then how do the other studies compare?

Wind tunnel testing is very expensive. Who is going to pay for 2-4 hours of tunnel time just to test shaved legs? For just one person. To do a real study with a bunch of riders like Specialized did would probably take several days of tunnel time. I believe commercial tunnels cost in the vicinity of $10k a day. Who's going to pay for that? As somebody else mentioned before the manufacturers aren't going to do it. They don't care. Any individual who is paying for their own tunnel time is already shaving their legs and if they are wondering, they aren't going to spend the close to $1,000 for the tunnel time it would take to test this.

I believe that the Specialized tunnel is completely unique in that they have the leeway to do this kind of thing. Other tunnels need to make money to stay open. I would imagine that the Specialized tunnel falls into a mixture of R&D and Marketing overhead costs for Specialized.

Basically, it's a whole lot cheaper to play better safe than sorry and shave your legs than it was to spend money on tunnel time to find out for sure.

Kevin

http://kevinmetcalfe.dreamhosters.com
My Strava
Quote Reply
Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
I wouldn't entirely agree with this. Yes trees/foliage will change the wind speed you might have expected at ground level if you were modeling things, but generally if you take a rider with a wind tunnel measured CdA, have them do a time trial, run the power meter data through the equations of motion of cycling, you get results accurate within a few seconds.

Or, you can look at the TT results and compute the power the cyclist must have done and compare that to the measured power, and that is also very close, see: http://www.recumbents.com/...20road%20cycling.pdf

Given the numerous confounding factors, such as not having perfect data about ambient wind, power meters not being perfectly accurate, riders not holding their wind tunnel positions perfectly all the time, that modeled vs measured data is so close suggests a wind tunnel represents the real world very, very well.


aaronechang wrote:

The wind tunnel is the same thing - results in the wind tunnel often do not match up with what you get in the real world. Boardman talked about how surrounding trees / foliage and buildings would often complicate things, especially when you're talking about things like dirty air caused by rotating wheels and churning legs.

+1 jackmott's comments. We use three "tools/methods" for aero research - on road/track, win(d) tunnel, and CFD. Each has its strengths and weaknesses but each is setup to represent real world conditions. We do a ton of correlation work to make sure that what we measure in one tool is calibrated to the experience on the road.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
Quote Reply
Re: Shaved Legs = 15 watts? [nslckevin] [ In reply to ]
Quote | Reply
nslckevin wrote:
Wind tunnel testing is very expensive. Who is going to pay for 2-4 hours of tunnel time just to test shaved legs? For just one person. To do a real study with a bunch of riders like Specialized did would probably take several days of tunnel time. I believe commercial tunnels cost in the vicinity of $10k a day. Who's going to pay for that? As somebody else mentioned before the manufacturers aren't going to do it. They don't care. Any individual who is paying for their own tunnel time is already shaving their legs and if they are wondering, they aren't going to spend the close to $1,000 for the tunnel time it would take to test this.

I believe that the Specialized tunnel is completely unique in that they have the leeway to do this kind of thing. Other tunnels need to make money to stay open. I would imagine that the Specialized tunnel falls into a mixture of R&D and Marketing overhead costs for Specialized.

Basically, it's a whole lot cheaper to play better safe than sorry and shave your legs than it was to spend money on tunnel time to find out for sure.

Well your last point also applies to just about anything that people buy to gain free speed - wheel sets, helmets, skin suits, shoe covers. All of these cost less than a day in the wind tunnel so should we just be safe and buy them all?

I agree that no one would spend thousands of dollars to just to test shaved legs, since they're probably doing it anyways if they're at that level. But lots of people rent out wind tunnels for days at a time to test dozens of variables, and I just found it curious that no one else thought to just test shaved legs for the heck of it (until Specialized just did).
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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This really makes me like Specialized.
You will have my heart next bike I buy.
Thanks for the info
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Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
Some people assuredly have tested it, and not told anybody.

Well here's another question I have - if this is true, then either they found the same thing Specialized did and kept it to themselves (unlikely). Or what they found mirrored what everyone previous figured (shaved legs don't make a significant difference). If it's the former, you can bet I'd let other people know about it. Because an 8% drag reduction is very significant. If it's the latter, then that's valuable to know as well.

It's great that Specialized has done this study, and I hope there will be future studies to compare it with. Because ultimately that's how everyone comes to a consensus on something - peer-reviewed studies and tests either put forth or confirm hypotheses, and eventually they become accepted as fact. It's a shame that we can't take a closer look at the previous study done by Chester Kyle. If we could, then it would possibly even further strengthen the case for shaving your legs, if it can be proven that Kyle's study was flawed in some way or was less rigorous than Specialized's. The converse could also be true.
Quote Reply
Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
Quote | Reply
aaronechang wrote:

Well here's another question I have - if this is true, then either they found the same thing Specialized did and kept it to themselves (unlikely).

Why do you find that unlikely?

I find it very likely.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
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Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
Quote | Reply
  

>I find it very likely.

If I were Specialized I would have created a really annoying Slowtwitch ad titled, "This one WEIRD trick can save you 70 seconds over 40K! Wives and girlfriends HATE us." And then charged $25 for a whitepaper that basically said, "Shave, bitches."
Last edited by: trail: Jul 2, 14 10:35
Quote Reply
Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
Quote | Reply
So I take it Specialized is coming out with a new collaboration with Gillette?

"When the going gets weird, the weird turn pro."
Hunter S. Thompson
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Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
Why do you find that unlikely?
the amount of times they could have been right on the internet when a "should I shave" thread popped up for one ;)

My Blog - http://leegoocrap.blogspot.com
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Re: Shaved Legs = 15 watts? [tri-tele] [ In reply to ]
Quote | Reply
tri-tele wrote:
So I take it Specialized is coming out with a new collaboration with Gillette?

I hope it is a tri specific razor, I ain't using no roadie razor!
Quote Reply
Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
Quote | Reply
MITaerobike wrote:
jackmott wrote:
I wouldn't entirely agree with this. Yes trees/foliage will change the wind speed you might have expected at ground level if you were modeling things, but generally if you take a rider with a wind tunnel measured CdA, have them do a time trial, run the power meter data through the equations of motion of cycling, you get results accurate within a few seconds.

Or, you can look at the TT results and compute the power the cyclist must have done and compare that to the measured power, and that is also very close, see: http://www.recumbents.com/...20road%20cycling.pdf

Given the numerous confounding factors, such as not having perfect data about ambient wind, power meters not being perfectly accurate, riders not holding their wind tunnel positions perfectly all the time, that modeled vs measured data is so close suggests a wind tunnel represents the real world very, very well.


aaronechang wrote:

The wind tunnel is the same thing - results in the wind tunnel often do not match up with what you get in the real world. Boardman talked about how surrounding trees / foliage and buildings would often complicate things, especially when you're talking about things like dirty air caused by rotating wheels and churning legs.


+1 jackmott's comments. We use three "tools/methods" for aero research - on road/track, win(d) tunnel, and CFD. Each has its strengths and weaknesses but each is setup to represent real world conditions. We do a ton of correlation work to make sure that what we measure in one tool is calibrated to the experience on the road.

Mark

I know what one of the first things I'm going to check on the "half-pipe" this summer is going to be ;-)

http://bikeblather.blogspot.com/
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Re: Shaved Legs = 15 watts? [AG] [ In reply to ]
Quote | Reply
The effect of compression calfs in aerodynamics is interesting. As the long sleever trisuits are hot topic, the compression calfs should have similar effect. The good question is, what is the fastest compression calf. This is the only reason i use compression calfs on race, just dont have data on this topic..

—
Quote Reply
Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
Quote | Reply
aaronechang wrote:
Well here's another question I have - if this is true, then either they found the same thing Specialized did and kept it to themselves (unlikely).
Most top riders won't even reveal their power data. Why not? If they upload a file to Strava with power data then you can download it and aerolab it. You can then see what they have changed between different TTs and see the effect on their CdA. They don't want you to do that. As Michael Hutchinson noted in his book, we aren't looking for free speed, we are looking for free speed that nobody else has. Performance is relative not absolute, if you find a source of improvement and everyone else finds it too, you haven't improved at all.
Quote Reply
Re: Shaved Legs = 15 watts? [steelerguy] [ In reply to ]
Quote | Reply
steelerguy wrote:
tri-tele wrote:
So I take it Specialized is coming out with a new collaboration with Gillette?


I hope it is a tri specific razor, I ain't using no roadie razor!

McLaren Gillette with carbon-fiber blades.
Quote Reply
Re: Shaved Legs = 15 watts? [bostonalex] [ In reply to ]
Quote | Reply
No. Shaving your nuts probably won't net you any additional speed. But your wife may appreciate it.

bostonalex wrote:
Insane. Absolutely insane to see the #'s... Shaving your legs is completely free speed... Nuts. I think my wife would divorce me.
Quote Reply
Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
Quote | Reply
jackmott wrote:
Some people assuredly have tested it, and not told anybody.

It has been tested before. I have also personally seen a beard test in the tunnel a few years back.
Quote Reply
Re: Shaved Legs = 15 watts? [jackmott] [ In reply to ]
Quote | Reply
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.
Quote Reply
Re: Shaved Legs = 15 watts? [Steve Irwin] [ In reply to ]
Quote | Reply
>Why not? If they upload a file to Strava with power data then you can download it and aerolab it. You can then see what they have changed between different TTs and see the effect on their CdA. They don't want you to do that.

Why don't they want you to do that? If I were Spartacus or the Panzerwagen I'd post everything and say: "Here it is. Can you beat that? Good luck!" Psychological warfare. Sort of like when Lance was briefly posting his triathlon workouts to Strava. You're making people worry about you instead of worrying about optimizing their own preparation. I think a lot of the secretiveness over power data is kind of silly.

>As Michael Hutchinson noted in his book, we aren't looking for free speed, we are looking for free speed that nobody else has. Performance is relative not absolute, if you find a source of improvement and everyone else finds it too, you haven't improved at >all.

There are very few things that "nobody" else has. We're trying to approach optimal performance given the constraints we have. I could be wrong, but I don't think there are really that many secrets out there (excepting doping). No secret training plans. No secret aero positions. No equipment secrets. What there is a general shortage of, is people who take the time to rigorously and consistently apply all the knowledge that's *freely available.*.
Quote Reply
Re: Shaved Legs = 15 watts? [John Cobb] [ In reply to ]
Quote | Reply
Interesting, what sorts of things could explain the discrepancy of that magnitude I wonder?

I mean, obviously a spreadsheet with some bad math that does the seconds saved calculation could do it, heh


John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.



Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter
Last edited by: jackmott: Jul 2, 14 13:41
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
Quote | Reply
aaronechang wrote:
jackmott wrote:
Some people assuredly have tested it, and not told anybody.


Well here's another question I have - if this is true, then either they found the same thing Specialized did and kept it to themselves (unlikely). Or what they found mirrored what everyone previous figured (shaved legs don't make a significant difference). If it's the former, you can bet I'd let other people know about it. Because an 8% drag reduction is very significant. If it's the latter, then that's valuable to know as well.

It's great that Specialized has done this study, and I hope there will be future studies to compare it with. Because ultimately that's how everyone comes to a consensus on something - peer-reviewed studies and tests either put forth or confirm hypotheses, and eventually they become accepted as fact. It's a shame that we can't take a closer look at the previous study done by Chester Kyle. If we could, then it would possibly even further strengthen the case for shaving your legs, if it can be proven that Kyle's study was flawed in some way or was less rigorous than Specialized's. The converse could also be true.

I emailed Chet to try and get a copy of his paper. I only have his papers back to 1989, nothing earlier than that. He gave me copies when we were working together years ago. The godfather of cycling aero, Chet Kyle - great guy and awesome mentor.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
Quote Reply
Re: Shaved Legs = 15 watts? [John Cobb] [ In reply to ]
Quote | Reply
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.

Not sure what to say. I can give you all the raw CdA's if you need them. We were so concerned about the data that we checked out balance cal the days of the first two tests. We wouldn't put this data out without a TON of data and a bit of statistical analysis. Even with Keith, the subject of the video, a t-stat for 99% would give us a 82 sec +/- 20 sec range (I need to verify this data for all). Note our data is ONLY head on in this case but we've been pretty real about how we're testing and the results are extremely consistent.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
Quote Reply
Re: Shaved Legs = 15 watts? [John Cobb] [ In reply to ]
Quote | Reply
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.

Shaving leg hair being on par with an aero helmet or a disc wheel? Sure, seems legit to me...

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly
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Re: Shaved Legs = 15 watts? [JasoninHalifax] [ In reply to ]
Quote | Reply
JasoninHalifax wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Shaving leg hair being on par with an aero helmet or a disc wheel? Sure, seems legit to me...

I really hope that this turns out to be a big prank. I have a race this weekend and I'm really hoping the joke is exposed before then. If I shave my legs, and it turns out to be useless, Im going to be very, very unhappy. But, for 50 seconds, I would shave my head.
Quote Reply
Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
Quote | Reply
MITaerobike wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Not sure what to say. I can give you all the raw CdA's if you need them. We were so concerned about the data that we checked out balance cal the days of the first two tests. We wouldn't put this data out without a TON of data and a bit of statistical analysis. Even with Keith, the subject of the video, a t-stat for 99% would give us a 82 sec +/- 20 sec range (I need to verify this data for all). Note our data is ONLY head on in this case but we've been pretty real about how we're testing and the results are extremely consistent.

Mark

Would have been nice to have tested two groups:
- shave lower legs only first, then complete legs
- shave upper legs only first, then complete legs
Quote Reply
Re: Shaved Legs = 15 watts? [aries33] [ In reply to ]
Quote | Reply
aries33 wrote:
JasoninHalifax wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Shaving leg hair being on par with an aero helmet or a disc wheel? Sure, seems legit to me...

I really hope that this turns out to be a big prank. I have a race this weekend and I'm really hoping the joke is exposed before then. If I shave my legs, and it turns out to be useless, Im going to be very, very unhappy. But, for 50 seconds, I would shave my head.

I'm pretty sure Ashton Kutcher is running the wind tunnel....

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly
Quote Reply
Re: Shaved Legs = 15 watts? [JasoninHalifax] [ In reply to ]
Quote | Reply
JasoninHalifax wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Shaving leg hair being on par with an aero helmet or a disc wheel? Sure, seems legit to me...


do aero helmets and disc wheels have hair? :P
I think it's telling when companies come out with designs that have simple modifications and they yield "significant" results (remember when dimples first became popular?).
that being said, if you're fat, and have dimples on your butt, if you shave and expose them on the ride, would you gain 50 seconds on a 40km tt?

haha...i'm laughing at myself...and yes, wine is involved.
Last edited by: d00d: Jul 2, 14 16:54
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Re: Shaved Legs = 15 watts? [d00d] [ In reply to ]
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d00d wrote:
JasoninHalifax wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Shaving leg hair being on par with an aero helmet or a disc wheel? Sure, seems legit to me...


do aero helmets and disc wheels have hair? :P
I think it's telling when companies come out with designs that have simple modifications and they yield "significant" results (remember when dimples first became popular?).
that being said, if you're fat, and have dimples on your butt, if you shave and expose them on the ride, would you gain 50 seconds on a 40km tt?

haha...i'm laughing at myself...and yes, wine is involved.

Of course they don't have hair, if they had hair then they'd be slow. But dimples are way faster, because reasons...

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
Quote | Reply
MITaerobike wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Not sure what to say. I can give you all the raw CdA's if you need them. We were so concerned about the data that we checked out balance cal the days of the first two tests. We wouldn't put this data out without a TON of data and a bit of statistical analysis. Even with Keith, the subject of the video, a t-stat for 99% would give us a 82 sec +/- 20 sec range (I need to verify this data for all). Note our data is ONLY head on in this case but we've been pretty real about how we're testing and the results are extremely consistent.

Mark

Speaking of that, where are your error bars on the graph?? ;-)

Plus, I'm asking again for "before" pics for the range of Chewbaccas tested...please? :-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Shaved Legs = 15 watts? [BMANX] [ In reply to ]
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BMANX wrote:
What about going from very hairy and using an electric shaver to trim down but still having stubble and not doing the full shave. Thoughts.


That is a very good question.

I wonder if an optimum amount of stubble would trip the boundary layer like (dare I say it) wheel dimples...


EDIT: Then, there is this: http://www.slowtwitch.com/...erformance_4255.html


"100% of the people who confuse correlation and causation end up dying."
Last edited by: MOP_Mike: Jul 2, 14 17:16
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Re: Shaved Legs = 15 watts? [MOP_Mike] [ In reply to ]
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Clippers are so fast on the legs
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Re: Shaved Legs = 15 watts? [Tom A.] [ In reply to ]
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Tom A. wrote:
MITaerobike wrote:
John Cobb wrote:
I tested this leg hair question in '87 and again in 1995 at Texas A&M, I only tested one rider in each test situation but I recall that the hair amount was what we considered average. I do know we did full yaw sweeps but the gains were from zero to just a couple of seconds over the yaw range. I mean really? 70 seconds? 15 watts? I know a lot of things have changed with aero frames, positions and aero helmets used during the test but water bottle interference and calf shape and sizing will really effect the airflow shapes. Legs are just exposed cylinders to the air, so muscle shapes and leg lengths will matter. I'm glad Specialized is doing some testing and I know they are trying to be thorough but on road data with some power meters will be interesting to compare these results with.


Not sure what to say. I can give you all the raw CdA's if you need them. We were so concerned about the data that we checked out balance cal the days of the first two tests. We wouldn't put this data out without a TON of data and a bit of statistical analysis. Even with Keith, the subject of the video, a t-stat for 99% would give us a 82 sec +/- 20 sec range (I need to verify this data for all). Note our data is ONLY head on in this case but we've been pretty real about how we're testing and the results are extremely consistent.

Mark


Speaking of that, where are your error bars on the graph?? ;-)

Plus, I'm asking again for "before" pics for the range of Chewbaccas tested...please? :-)

sorry got stacked at work today - give me a day and I'll give you both.

--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Re: Shaved Legs = 15 watts? [MOP_Mike] [ In reply to ]
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I'm sorry, I just realized that I have completely overlooked a whole new market for products. I'll need to consult with Josh @Silca but now with the fashionable compression socks that racers wear, I think I will come out with some leg moulds that you put on under the socks. Then right before the race you rip all that off and you'll have some good dimpled leg skin. Hair or not shouldn't really matter if you get the dimple pattern right. I'm seeing the whole new thing where we put team names or clubs names in the dimple pattern and then you could just shave the high areas to give some good contrast. Oh yeah, check my web site soon..
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Re: Shaved Legs = 15 watts? [coates_hbk] [ In reply to ]
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Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage. I'm married and I shave and it works for us. Having said that I don't believe it makes you significantly faster over any distance.
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Re: Shaved Legs = 15 watts? [Dinsky11] [ In reply to ]
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so how many seconds slower would the infamous slowtwich gorilla be in a 40k TT? 3 minutes vs. the shaved man? I will volunteer to wear the gorilla suit when you decide to test this. keep me in mind.

in all seriousness, if two shaved legs makes a 15w difference, you guys at specialized better be finding ways multiple ways to make your bikes 15 w faster!
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Re: Shaved Legs = 15 watts? [leegoocrap] [ In reply to ]
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leegoocrap wrote:
I agree... Some pretty odd things have been tested in the tunnel... I just have a hard time thinking this never came up before as often as it's given as a reason to shave your legs.
Admittedly it could've been tested and the info just never got out, and repeatability is there (w/ multiple athletes) in what Spec has put out.

Glad I've always shaved nonetheless. (I always did it because of the cultural thing...)

The people sponsoring the testing weren't selling razors. Thereyago.



------------------

- I do all my own stunts
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Re: Shaved Legs = 15 watts? [JanneK] [ In reply to ]
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JanneK wrote:
The effect of compression calfs in aerodynamics is interesting. As the long sleever trisuits are hot topic, the compression calfs should have similar effect. The good question is, what is the fastest compression calf. This is the only reason i use compression calfs on race, just dont have data on this topic..


A few years ago David Warden tested some apparel and tested a few compression sleeves. Give it a listen. http://tri-talk.com/77/ But I would assume like most aero benefits, it's dependent on the individual and not this brand is better is always better.
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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I just have to say, as a fellow graduate from the 'tute, I believe you, but I'm very disappointed to see these results. I never ever really considered shaving before, but now, to learn it's as effective as an Aero helmet?

My wife didn't say that she would divorce me, but I did get the 'aren't you just doing this for fun?' response.

I've still got a few weeks to work on her before my next triathlon.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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15 watts?! I don't buy it. The combined additional frontal footprint added by average leg hair (vs no hair) can't equal even one additional exposed brake cable and there's no way that's going to be 15 watts. I know, I know - can't argue with the numbers. Something is up here. Flame away..
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Re: Shaved Legs = 15 watts? [Rick in the D] [ In reply to ]
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Rick in the D wrote:
leegoocrap wrote:
I agree... Some pretty odd things have been tested in the tunnel... I just have a hard time thinking this never came up before as often as it's given as a reason to shave your legs.
Admittedly it could've been tested and the info just never got out, and repeatability is there (w/ multiple athletes) in what Spec has put out.

Glad I've always shaved nonetheless. (I always did it because of the cultural thing...)


The people sponsoring the testing weren't selling razors. Thereyago.

BS... I've seen Gillette's Mach3 commercials and they've got fighter jets... they've been to the tunnel. ;)

My Blog - http://leegoocrap.blogspot.com
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Re: Shaved Legs = 15 watts? [TriBiker] [ In reply to ]
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TriBiker wrote:
15 watts?! I don't buy it. The combined additional frontal footprint added by average leg hair (vs no hair) can't equal even one additional exposed brake cable and there's no way that's going to be 15 watts. I know, I know - can't argue with the numbers. Something is up here. Flame away..

Believe me, that was my exact reaction after testing the first couple of people. We still haven't spent enough time to answer the "why" - this was just the "what." One thing to keep in mind is that frontal area is not everything and in this case likely isn't the primary factor. An interesting anecdote: men and women use different balls in tennis. The felt/fuzz on the men's ball is thicker to slow down the game (or conversely speed up the women's game with a lighter felt ball).

Chris Yu
Applied Technology
Specialized Bicycle Components
@chrisyuinc
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Re: Shaved Legs = 15 watts? [steelerguy] [ In reply to ]
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"no roadie razor"

Roadies are great shavers--around all the bumps, corners of the knees, odd contours.

Trigeeks will only be able to shave two long straight patches on our shins and thighs.

__________
"At the end he was staggering into parked cars and accusing his support-van driver of trying to poison him." A description of John Dunbar in the 1st Hawaii Iron Man
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Re: Shaved Legs = 15 watts? [chrisyu] [ In reply to ]
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One more suggestion for testing... I'm sure it's minimal (if measurable) but what is the difference between an uncut steerer tube and one that is cut to size?

-------------------
Madison photographer Timothy Hughes | Instagram
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Re: Shaved Legs = 15 watts? [chrisyu] [ In reply to ]
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Just a matter of time before we start seeing this.... probably saved 40 watts.



-----------------------------------------------------------------
Founder: BestBikeSplit
Amazonian
Last edited by: Mrcooper: Jul 3, 14 4:29
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Re: Shaved Legs = 15 watts? [chrisyu] [ In reply to ]
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Theorically friction drag & interference drag could be at work here. The former is directly related to the surface area in contact with the fluid. These 60 hairs per square inch on your legs have some surface. The later is related to the interaction of the airflow around each individual hair. Two cylinders next to each other both facing the flow will have more drag combined than the sum of thier individual drag.

____________________________________
Pain is inevitable. Suffering is up to you.
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Re: Shaved Legs = 15 watts? [Dinsky11] [ In reply to ]
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Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage.
Completely agree. Maybe I'm a bit odd (well, I know I am) but I really don't understand the shaving=divorce thinking/attitude.

/Howie Nordström
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Re: Shaved Legs = 15 watts? [lllusion] [ In reply to ]
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lllusion wrote:
Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage.

Completely agree. Maybe I'm a bit odd (well, I know I am) but I really don't understand the shaving=divorce thinking/attitude.

she was only saying it as a joke..

as an aside, when i look at the competition in triathlons and see shaved legs i automatically think that person is fast. If i shave down, i better lift my game ;)
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Re: Shaved Legs = 15 watts? [lllusion] [ In reply to ]
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lllusion wrote:
Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage.

Completely agree. Maybe I'm a bit odd (well, I know I am) but I really don't understand the shaving=divorce thinking/attitude.

Hahahaha. Guys don't understand women and then don't understand why they don't understand women.






Take a short break from ST and read my blog:
http://tri-banter.blogspot.com/
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Re: Shaved Legs = 15 watts? [trail] [ In reply to ]
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trail wrote:
If I were Spartacus or the Panzerwagen I'd post everything and say: "Here it is. Can you beat that? Good luck!"
I think it would take incredible confidence to the point of arrogance to do that. If you're world champion, and you give away something that makes someone else better than you, and that loses you a ton of cash and world titles over the following years, you'd feel pretty stupid, wouldn't you? So the only reason you'd give away information that might make that happen is if you believe you are so much better than everyone else that there is nothing they can do that will make them match you. As I said, confidence to the point of arrogance.

trail wrote:
There are very few things that "nobody" else has. We're trying to approach optimal performance given the constraints we have. I could be wrong, but I don't think there are really that many secrets out there (excepting doping). No secret training plans. No secret aero positions. No equipment secrets.
Suppose that the latest information from Specialized on shaved legs is correct, we have a counter-example right there. It wasn't common knowledge that those time savings were available. But it's highly likely that some people did already know about it and didn't tell anyone. If they believed that there are no secrets, then there would be no point them telling anyone, as everyone would already know. OTOH if there are secrets, they have gained a valuable advantage over the competition, so again, no point telling anyone (unless they have confidence to the point of arrogance, or are so slow that they really don't care how anyone else performs relative to them). So whether there are secrets or not, either way there is no point them telling anyone about it. The situation for Specialized is relatively rare as they aren't trying to obtain an advantage, they did the research and published it as a marketing exercise, but I can see no reason why an individual athlete would have published such information in the past if they discovered it for themselves.
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Re: Shaved Legs = 15 watts? [apmoss] [ In reply to ]
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....the only thing you can be sure of is that the tri razor version will cost twice as much....
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Re: Shaved Legs = 15 watts? [Steve Irwin] [ In reply to ]
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>I think it would take incredible confidence to the point of arrogance to do that. If you're world champion

And that's also what it takes to be a world champion, generally.

>Suppose that the latest information from Specialized on shaved legs is correct, we have a counter-example right there.

I understand the concept of exploiting arbitrage. I'm sure there are other examples of proprietary knowledge that gives an advantage. I just think you're overstating its importance in the grand scheme of things.
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Re: Shaved Legs = 15 watts? [Tri-Banter] [ In reply to ]
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Should horses be shaved before races? Seems like it would help.
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Re: Shaved Legs = 15 watts? [apmoss] [ In reply to ]
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apmoss wrote:
"no roadie razor"

Roadies are great shavers--around all the bumps, corners of the knees, odd contours.

Trigeeks will only be able to shave two long straight patches on our shins and thighs.

You've seen all the people riding out of aero on their TT bikes right? With an aero helmet? All those heel strikers in Newtons? We love to spend more on stuff that makes us faster to then use it completely wrong! :)
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Re: Shaved Legs = 15 watts? [rijndael] [ In reply to ]
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rijndael wrote:
Wow is right. That's like upgrading to a set of Zipp 404s, for free.

Maybe Zipp will partner with Bic to introduce a line of carbonfiber razors selling for $129.99 a piece.

Remember - It's important to be comfortable in your own skin... because it turns out society frowns on wearing other people's
Quote Reply
Re: Shaved Legs = 15 watts? [chrisyu] [ In reply to ]
Quote | Reply
chrisyu wrote:
TriBiker wrote:
15 watts?! I don't buy it. The combined additional frontal footprint added by average leg hair (vs no hair) can't equal even one additional exposed brake cable and there's no way that's going to be 15 watts. I know, I know - can't argue with the numbers. Something is up here. Flame away..

Believe me, that was my exact reaction after testing the first couple of people. We still haven't spent enough time to answer the "why" - this was just the "what." One thing to keep in mind is that frontal area is not everything and in this case likely isn't the primary factor. An interesting anecdote: men and women use different balls in tennis. The felt/fuzz on the men's ball is thicker to slow down the game (or conversely speed up the women's game with a lighter felt ball).

Unexpected results, and then trying to figure out why, are my favorite part of testing. Keep up the good work, Chris, & congrats on the degree!

Jim Manton / ERO Sports
Quote Reply
Re: Shaved Legs = 15 watts? [Dinsky11] [ In reply to ]
Quote | Reply
Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage. I'm married and I shave and it works for us. Having said that I don't believe it makes you significantly faster over any distance.


Yeah. All that science and testing and multiple subjects in a world-class tunnel all seeing significant gains, forget it. It's what you believe that counts.

"The affliction that's the curse for the modern man. If you believe then you can't be wrong. Reject all the opposing opinions and carry on." - Affliction by Pennywise
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Re: Shaved Legs = 15 watts? [dgunthert] [ In reply to ]
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well, until someone else replicates this using their own independent protocol, preferably in a different facility, I'm a little skeptical, considering that it doesn't line up with any real world results that I've ever noticed.

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly
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Re: Shaved Legs = 15 watts? [dgunthert] [ In reply to ]
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dgunthert wrote:
Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage. I'm married and I shave and it works for us. Having said that I don't believe it makes you significantly faster over any distance.


Yeah. All that science and testing and multiple subjects in a world-class tunnel all seeing significant gains, forget it. It's what you believe that counts.

"The affliction that's the curse for the modern man. If you believe then you can't be wrong. Reject all the opposing opinions and carry on." - Affliction by Pennywise

Well within the space of this thread we've already identified 2 other prior tests of this that show little advantage in shaving - John Cobb's and Chester Kyle. So if you believe you can reduce drag by 8% simply by shaving your legs then you're choosing to believe that test and choosing to ignore the results of the previous tests. Just saying.
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Re: Shaved Legs = 15 watts? [Jim@EROsports] [ In reply to ]
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Thanks Jim...we both know that you have to throw in some/weird fun stuff to keep it interesting!

Chris Yu
Applied Technology
Specialized Bicycle Components
@chrisyuinc
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Re: Shaved Legs = 15 watts? [Doubletime] [ In reply to ]
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Doubletime wrote:
rijndael wrote:
Wow is right. That's like upgrading to a set of Zipp 404s, for free.


Maybe Zipp will partner with Bic to introduce a line of carbonfiber razors selling for $129.99 a piece.

SHUT UP AND TAKE MY MONEY!

:)
Quote Reply
Re: Shaved Legs = 15 watts? [dgunthert] [ In reply to ]
Quote | Reply
dgunthert wrote:
Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage. I'm married and I shave and it works for us. Having said that I don't believe it makes you significantly faster over any distance.


Yeah. All that science and testing and multiple subjects in a world-class tunnel all seeing significant gains, forget it. It's what you believe that counts.

"The affliction that's the curse for the modern man. If you believe then you can't be wrong. Reject all the opposing opinions and carry on." - Affliction by Pennywise

Especially if you're racing with me in M35-39...believe away!

Aaron Bales
Lansing Triathlon Team
Quote Reply
Re: Shaved Legs = 15 watts? [noofus] [ In reply to ]
Quote | Reply
noofus wrote:
Doubletime wrote:
rijndael wrote:
Wow is right. That's like upgrading to a set of Zipp 404s, for free.


Maybe Zipp will partner with Bic to introduce a line of carbonfiber razors selling for $129.99 a piece.


SHUT UP AND TAKE MY MONEY!

:)

only if they're dimpled....

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:
Well within the space of this thread we've already identified 2 other prior tests of this that show little advantage in shaving - John Cobb's and Chester Kyle
I wonder what riding position each test was done in. Specialized's appears to have been done riding on the hoods, which we might expect to show a bigger saving vs the TT position where your legs spend some of the time drafting behind your arms.

What would be very interesting would be to test the same subjects at weekly intervals to see if a gradual increase in drag can be seen as the hair grows back.
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Re: Shaved Legs = 15 watts? [Steve Irwin] [ In reply to ]
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Look at the plots above, it shows them.
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Re: Shaved Legs = 15 watts? [agreif] [ In reply to ]
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Okay, yes, I see the Specialized data shows the positions and there were a variety of positions. Do we know what position Cobb's and Kyle's tests used? Not that it seems to make all that much difference based on Specialized's data.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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These threads about shaving have infiltrated my subconscious. Last night I had a dream about a contentious ST shaving thread. In the dream, shaving was standard practice, but it was done during the race as part of T1. The big disagreement on the thread was whether people should use a blade or portable electric razor…

I should probably lay off the ST for awhile.
Quote Reply
Re: Shaved Legs = 15 watts? [Doubletime] [ In reply to ]
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Doubletime wrote:
rijndael wrote:
Wow is right. That's like upgrading to a set of Zipp 404s, for free.


Maybe Zipp will partner with Bic to introduce a line of carbonfiber razors selling for $129.99 a piece.

HUGE opportunity for WTC to hock razors right in the middle of race coverage. "Like a blender, but for your legs."

----------------------------------------------------------
Zen and the Art of Triathlon. Strava Workout Log
Interviews with Chris McCormack, Helle Frederikson, Angela Naeth, and many more.
http://www.zentriathlon.com
Quote Reply
Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:
dgunthert wrote:
Dinsky11 wrote:
Honestly I don't understand this. Your wife married you because of you, not your legs (regardless of what she might say). You have done the work and it is your body. Shave if you believe it gives you an advantage. I'm married and I shave and it works for us. Having said that I don't believe it makes you significantly faster over any distance.


Yeah. All that science and testing and multiple subjects in a world-class tunnel all seeing significant gains, forget it. It's what you believe that counts.

"The affliction that's the curse for the modern man. If you believe then you can't be wrong. Reject all the opposing opinions and carry on." - Affliction by Pennywise


Well within the space of this thread we've already identified 2 other prior tests of this that show little advantage in shaving - John Cobb's and Chester Kyle. So if you believe you can reduce drag by 8% simply by shaving your legs then you're choosing to believe that test and choosing to ignore the results of the previous tests. Just saying.

True, but it looks as though Specialized tested more than the other two and with multiple athletes (unless I've missed something).

This reminds me of all the bta testing we've done. My guess is we've done as much, if not more, than anyone, and for the longest time we just couldn't reproduce the numbers Cervelo saw which, lets face it, really started the whole bta fad. We'd see small decreases in drag with Xlab's Torpedo, but no where near 5 watts. Still it was consistent while all other setups appeared benign with the exception of one which was consistently worse. Then we tested with Speefil and, boom, 6 watts consistently every time we tested. Was it their bottle or the setup? I now know it was the setup, and it was David from Speedfil who knew exactly how to set it up for the best results. It was also no accident that their cage helped with proper setup.

I guess my point is this: We could have easily said the bta fad was a big fraud and that Cervelo's numbers were just an outlier based on numerous tests and substantial data we'd obtained. More testing proved the numbers to be correct; we just had to get the setup right. One test doesn't tell me a whole lot. I tend to become a believer when I see multiple tests with multiple setups and/or athletes. So, right now, I tend to lean towards the Specialized numbers. Perhaps I'm wrong...it certainly wouldn't be the first time!

Jim Manton / ERO Sports
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Re: Shaved Legs = 15 watts? [Jim@EROsports] [ In reply to ]
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In medicine and science, if other researchers are able to re-run your experiment and obtain the same results, then you can be pretty sure that they're the real deal. Until then - most researchers will remain skeptical of any outlier results. That's just a fact of life in science (to remain skeptical until proven otherwise). I realize it takes a lot of money and effort (none of which I am able to provide myself), but I'd be interested in seeing someone else try to reproduce these same results in a different wind tunnel. So while Specialized did a good job of running the test multiple times with different riders, it's still "one test". Another test run by a separate lab using the same methodology (but different testers and equipment) would rule out any variables such as testing equipment and would truly test whether the premise (shaved legs = 4-7% aero gains) is correct.

At the moment, this is the only experiment on shaved legs that shows significant gains. For all I know there may have been hundreds of other experiments that show the same results (or disprove them), but there have only been a handful that have been made public and that we know about. Of the ones we do know about - they don't quite match up with this experiment's results. That doesn't mean that this experiment is wrong, though.
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Re: Shaved Legs = 15 watts? [chrisyu] [ In reply to ]
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Real question: given these results, how much do you think that shaving my head would help when wearing a non-aero helmet such as the Prevail?
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Re: Shaved Legs = 15 watts? [Jim@EROsports] [ In reply to ]
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[url mailto:Jim@EROsports wrote:
Jim@EROsports[/url]] More testing proved the numbers to be correct; we just had to get the setup right.

Do you mean that you had a good bike setup that improved with a the correct placement of a speedfil BTA
or
if you have a bad enough setup, the speedfil will improve your aerodynamics?

I am not trying to be difficult, I am just not sure if I should interpret you r comment to mean
"Go get a speedfil and set it up right"
or
we found the right setup to show a 6w reduction by adding a speedfil, but it may not have necessarily been a great setup initially.

@christopher_borden •
Spinning Spoke • Dimond Bikes • Flo Cycling • Castelli Cycling
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Re: Shaved Legs = 15 watts? [durk onion] [ In reply to ]
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durk onion wrote:
Real question: given these results, how much do you think that shaving my head would help when wearing a non-aero helmet such as the Prevail?

haha, honestly don't know if we could give a general answer since hair styles & amount is so variable. Wouldn't be surprised if we saw something interesting though. A lot of the aero road helmets (including the Evade) rely heavily on managing internal flow. We've done a ton of Prevail vs. Evade tests so we might be able to see if shorter/no hair correlates with a bigger difference between the two but wouldn't be able to say if 1 athlete would be faster with the same helmet, but a shaved head.

You want to volunteer? =)

Chris Yu
Applied Technology
Specialized Bicycle Components
@chrisyuinc
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:
In medicine and science, if other researchers are able to re-run your experiment and obtain the same results, then you can be pretty sure that they're the real deal. Until then - most researchers will remain skeptical of any outlier results. That's just a fact of life in science (to remain skeptical until proven otherwise). I realize it takes a lot of money and effort (none of which I am able to provide myself), but I'd be interested in seeing someone else try to reproduce these same results in a different wind tunnel. So while Specialized did a good job of running the test multiple times with different riders, it's still "one test". Another test run by a separate lab using the same methodology (but different testers and equipment) would rule out any variables such as testing equipment and would truly test whether the premise (shaved legs = 4-7% aero gains) is correct.

At the moment, this is the only experiment on shaved legs that shows significant gains. For all I know there may have been hundreds of other experiments that show the same results (or disprove them), but there have only been a handful that have been made public and that we know about. Of the ones we do know about - they don't quite match up with this experiment's results. That doesn't mean that this experiment is wrong, though.

Totally agree with your notes, @aaronechang. I hope that these results perk up some interest for others to study this a bit and we won't stop either. We need to do some on-road/velodrome correlations but honestly, we can only do what we can afford to do. We've still gotta make some new bikes and equipment.

For @TomA, I promised photos of before & after, results, and error bars. Here's to me leaving work late on 4th of July eve!

Here are the mean CdA values for each test with error bars representing a 95% confidence interval, per t-stat method with degrees of freedom between 2 and 12 depending upon the athlete and test case. Even if you take the most conservative estimates (the lower bar on each), there's substantial time/power savings.



And here's the before and after of each athlete (but I don't have photos of Luc):

Jesse Thomas - Dec 16, 2013
9 out of "chewbacca"


Mark - Feb 4, 2013
7 out of "chewbacca"


Aaron - Feb 4, 2013
6 out of "chewbacca"


James - Feb 19, 2014
4 out of "chewbacca"


Keith - June 24, 2014
8 out of "chewbacca"
(Note: scars were from mtn biking, not shaving)


Btw, while I was doing this, I thought, "huh, I have a lot of weird pictures of dudes legs on my phone". And immediately I was less into this project. That's it.

Mark

--
Mark Cote
MITAerobike
Specialized Bicycle Components
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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I think this thread has grown in a very responsible way and it's discussions like this that help our technology and sport grow. For my part and most others that would like to go test this further, you have to decide if there is a real good reason to spend the money. For me or most anybody else to go do a 4 - 6 hr tunnel test, it's going to cost me at least $3500.00 - $7000.00 with travel time and that is MY out of pocket money, not some huge corporations money, so I have to decide how much do I really care. I applaud Mark and Chris and Specialized for doing the test and for spending the resources on this and I am envious of them for having their own tunnel. But I think it is only fair that the masses do their due diligence and do their studies with roll downs, power meters or what ever so that we all can learn more. Time and technology keeps improving at a huge rate and each of us that are involved in the sport, whether as a business or just a racer will benefit and that should be the end game. I have found repeatedly over the years that tunnel time savings very rarely directly relate to actual real world savings of the exact amounts, so I always read these reports, including my own findings, with a little skepticism and I think that is fair for the consumers. So, yes, I believe that shaving your leg hair is good for some speed, I'm just waiting a little longer to decide how much speed.
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Re: Shaved Legs = 15 watts? [John Cobb] [ In reply to ]
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Well, at least this should be fairly easy for some people to test on their own. If you have access to a velodrome, or a nice loop with little wind...I can't see how difficult it would be to verify the 15 watt claim. I mean...we're not trying to validate a 2-3 watt difference like you would get from latex tubes...we're talking about 15 watts or 70 seconds per 40k. If some people come back with results in the 5-10 watt range that would still at least be a validation that it's worth doing. It's not fully necessary to replicate 15 watt improvements for this whole "is shaving worth it" argument to be settled.

Now on the other hand...if random people go out and test this on their own...and constantly report little to no difference in their results...then either they REALLY suck at testing protocols...or we might be back to square one.

ETA: I suppose you could make the testing process really easy. Instead of shaving your legs between runs (wind, air pressure, etc may change), just quickly slip on a calf sleeve or something that covers the hair. I know it may differ from how skin reacts...but most testing I've seen shows that skin isn't as aero as fabric anyway. Got to admit though...it would be pretty funny to see a triathlete sitting on the side of the road with his bike right next to him while shaving his legs...LOL.
Last edited by: Jason N: Jul 3, 14 19:12
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Re: Shaved Legs = 15 watts? [Jason N] [ In reply to ]
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Peoples . . .

While this has been a very fun discussion, there is some pretty good data here that THIS IS FREE SPEED!!!! REALLY!!! As in you don't have to buy any expensive toys - you just have to shave your legs dammit!

And I can speak for alot of the womens - we do think shaved legs are sexy!!!! Plus you are now on to our dirty little secret as to why so many of you get chicked . . .

I look forward to passing you dudes with hairy legs on the bike!

So just shave your legs dammit!
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Re: Shaved Legs = 15 watts? [John Cobb] [ In reply to ]
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The majority of this is WAY out of my depth, but let me stick my toe in.

If I correctly understand a roll down test, I wonder if it would not be such a good option. Does the pedaling action possibly contribute to added significance of leg hair?

Aaron Bales
Lansing Triathlon Team
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Re: Shaved Legs = 15 watts? [Jim@EROsports] [ In reply to ]
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Hey Jim,
You raise an interesting point on the Speedfill bottle setup. What IS the best setup? I've probably seen at least half a dozen setups different than how I have mine setup. I'll need to bring in my bottle to have you set it up for me on my next visit!

-Stu
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Re: Shaved Legs = 15 watts? [themadcyclist] [ In reply to ]
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themadcyclist wrote:
Peoples . . .

While this has been a very fun discussion, there is some pretty good data here that THIS IS FREE SPEED!!!! REALLY!!! As in you don't have to buy any expensive toys - you just have to shave your legs dammit!

And I can speak for alot of the womens - we do think shaved legs are sexy!!!! Plus you are now on to our dirty little secret as to why so many of you get chicked . . .

I look forward to passing you dudes with hairy legs on the bike!

So just shave your legs dammit!


I've consistently been in the top 1-2% of any field for bike splits, and I have never, ever shaved my legs.

So - apparently the only thing standing between me and TOTAL DOMINATION, is shaving my legs?
Somehow, I'm not buying that.

Disclaimers - since '08 or so, I've been wearng calf sleeves for most races, as I have semi-chronic calf running issues.
I'm probably a 6 on the Chewbacca scale, so maybe those larger gains are only for those on the Robin Williams end of the Wookie spectrum?
(perhaps, not unlike how wearing a wetsuit works better for truly awful swimmers - like me - vs. much less benefit to talented swimmers)


float , hammer , and jog

Last edited by: Murphy'sLaw: Jul 4, 14 7:04
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Thanks for the effort Mark!

As I suspected, I fall well below even the amount on your least hairy subject...I'd send you pics, but you probably wouldn't open them ;-)

Looks like I won't be able to be the one to do a field test confirmation :-(

http://bikeblather.blogspot.com/
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Re: Shaved Legs = 15 watts? [Jason N] [ In reply to ]
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Jason N wrote:
Now on the other hand...if random people go out and test this on their own...and constantly report little to no difference in their results...then either they REALLY suck at testing protocols...or we might be back to square one.
Unless you're only doing a small number of reps with each setup, it's very unlikely that someone with poor test protocol will find little to no difference between two setups. Suppose two setups differ by 10W, and someone does 4 reps per setup, and they all come out at around the same CdA. That would require 4 reps to have a random error of almost exactly 10W, while the other 4 were all spot on, or some similar alternative way of getting the same result. It's really very very unlikely. How poor test protocol typically manifests is with implausibly large differences between setups, because if your distribution has a large standard deviation the likelihood of the sample mean being a long way from the true mean is quite high, even with e.g. 4 reps per setup. If someone frequently tests changes and keeps finding only small differences between things, it's most likely that their testing is pretty good, whereas if someone keeps finding large differences between everything they test, it's most likely that their testing is poor.
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Re: Shaved Legs = 15 watts? [Steve Irwin] [ In reply to ]
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Another way to get a handle on the your test protocol quality is take the "Tom Compton Challenge" :-)

http://bikeblather.blogspot.com/...ng-chung-method.html



http://bikeblather.blogspot.com/
Last edited by: Tom A.: Jul 4, 14 15:06
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Re: Shaved Legs = 15 watts? [Murphy'sLaw] [ In reply to ]
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Murphy'sLaw wrote:
themadcyclist wrote:
Peoples . . .

While this has been a very fun discussion, there is some pretty good data here that THIS IS FREE SPEED!!!! REALLY!!! As in you don't have to buy any expensive toys - you just have to shave your legs dammit!

And I can speak for alot of the womens - we do think shaved legs are sexy!!!! Plus you are now on to our dirty little secret as to why so many of you get chicked . . .

I look forward to passing you dudes with hairy legs on the bike!

So just shave your legs dammit!


I've consistently been in the top 1-2% of any field for bike splits, and I have never, ever shaved my legs.

So - apparently the only thing standing between me and TOTAL DOMINATION, is shaving my legs?
Somehow, I'm not buying that.

Disclaimers - since '08 or so, I've been wearng calf sleeves for most races, as I have semi-chronic calf running issues.
I'm probably a 6 on the Chewbacca scale, so maybe those larger gains are only for those on the Robin Williams end of the Wookie spectrum?
(perhaps, not unlike how wearing a wetsuit works better for truly awful swimmers - like me - vs. much less benefit to talented swimmers)

All I am saying is that there seems to be some pretty good evidence that shaving legs saves you a few watts. Looking at the pictures, it is pretty clear the time savings does depend on position but the data shows a savings nonetheless! I don't buy 15W but while everyone quibbles about how many watts that might be based upon position or chewbacca factor, shaving your legs = FREE SPEED. Keeping track of all the little details does add up!

Looking forward to seeing what other studies these guys do in their spare time in the wind tunnel!
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Re: Shaved Legs = 15 watts? [themadcyclist] [ In reply to ]
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This is why scientific papers are peer reviewed by anonymous referees that are expert on the given field (though that system is not perfect either and there are lots of abuse).

Maybe that result is correct, maybe not, I'm not familiar enough to pass on a judgement, I would love other experts to reproduce the experiment and analyze the data independently.
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Re: Shaved Legs = 15 watts? [howlingmadbenji] [ In reply to ]
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Verry interesting! I whanted to test it on several occasions but in the end I allways didn't have the time and the mood to shave my legs in the velodrom. Anyway, I will ckeck it the next time on the track in automn or spring. Anything bigger than 5W at 45 km/h should be no problem with our protocol.

I ask me whether it is due to a boundary layer phenomenom? Or how do the aerodynamic Experte call it, drag crisis? The answer could give a cda measerement with variing air velocity.

One comment to peer review process. I get a paper to review about every week, guess how good I can do my job? I also get back lots of papers of your research group from reviewers in order to correct them. There are many stupid reviewers out there!
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Re: Shaved Legs = 15 watts? [Tom A.] [ In reply to ]
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Tom A. wrote:
Another way to get a handle on the your test protocol quality is take the "Tom Compton Challenge" :-)
http://www.trainingandracingwithapowermeter.com/...aerodynamicists.html
Last edited by: Andrew Coggan: Jul 4, 14 14:23
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Re: Shaved Legs = 15 watts? [Andrew Coggan] [ In reply to ]
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Andrew Coggan wrote:
Tom A. wrote:
Another way to get a handle on the your test protocol quality is take the "Tom Compton Challenge" :-)
http://www.trainingandracingwithapowermeter.com/...aerodynamicists.html

Is that your way of telling me my link was broken? All fixed now, thanks! ;-) I link to your blog post pretty early on in that...

http://bikeblather.blogspot.com/
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Re: Shaved Legs = 15 watts? [Steve Irwin] [ In reply to ]
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I'll be in the parking lot just east of here tomorrow morning (7/5) at 5:30 am with a razor:

33.1256658,-117.1579207


I'll be doing a small # of reps. this is what I will execute on my TT bike with both PT and SRM installed:




1) baseline ~50 psi lower tire pressure
2) hoods/sitting up
3) baseline

...shave...


1) baseline
2) hoods/sitting up
3) baseline ~50 psi lower tire pressure


if you are local, come out and join me. i'd be happy to help reduce your power meter data using the WLB method and chat about anything else you'd like to. runs will be 2 slow laps, 3 fast, 2 slow. I'll have cones out to help maintain lines - hopefully the wind will be calm. Should take a little over 75 minutes to complete things.


cheers,
-k


PS - I'm a 7/10 on the sasquatch scale - not sure how this compares to the wookie scale, though

PPS - I did some preliminary sniffing on this topic here - if it is this big, it should be detectable via field test. i'm curious to see what sorts out!







=================
Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================
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Re: Shaved Legs = 15 watts? [BikeTechReview] [ In reply to ]
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BikeTechReview wrote:
I'll be in the parking lot just east of here tomorrow morning (7/5) at 5:30 am with a razor:

33.1256658,-117.1579207


I'll be doing a small # of reps. this is what I will execute on my TT bike with both PT and SRM installed:

1) baseline ~50 psi lower tire pressure
2) hoods/sitting up
3) baseline

...shave...

1) baseline
2) hoods/sitting up
3) baseline ~50 psi lower tire pressure

if you are local, come out and join me. i'd be happy to help reduce your power meter data using the WLB method and chat about anything else you'd like to. runs will be 2 slow laps, 3 fast, 2 slow. I'll have cones out to help maintain lines - hopefully the wind will be calm. Should take a little over 75 minutes to complete things.

cheers,
-k


PS - I'm a 7/10 on the sasquatch scale - not sure how this compares to the wookie scale, though
PPS - I did some preliminary sniffing on this topic here - if it is this big, it should be detectable via field test. i'm curious to see what sorts out!

I shaved my legs in a parking lot...



I had to cut the last one short because there was a motorcycle riding class trying to set up, and overall not my best most cleanest riding (it's been maybe 5 years since I was on the TT bike!?!). Also, conditions were not perfectly dead calm, and I should have started 30 minutes earlier (sun came up and warmed up the pavement). I'm not super happy with Crr values as a result. But, these data are what they are. If someone wants the SRM file and PT file to do their own analysis we'll figure something out.

Who's next to test the shaving claim?

=================
Kraig Willett
http://www.biketechreview.com - check out our reduced report pricing
=================
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Re: Shaved Legs = 15 watts? [BikeTechReview] [ In reply to ]
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So shaved legs = faster, but I don't know how to convert your numbers into watts or time.

/kj

http://kjmcawesome.tumblr.com/
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Re: Shaved Legs = 15 watts? [BikeTechReview] [ In reply to ]
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What he said ^^^

If CxA is aero drag then it looks like the tests ranged from around 2% to 7-8% drag reduction?
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Re: Shaved Legs = 15 watts? [BikeTechReview] [ In reply to ]
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Here's my "test" from today. Last week I rode a 50 mile TT, and this week I rode a 25 mile TT on the same course against many of the same competitors. Conditions were much slower today due to wind speed and direction, so I don't think there is much point comparing aerolabbed CdAs, but for the 50 I had perhaps 3 months of hair growth on my legs, and I shaved them for today's 25. I took the gaps to all the riders in the top 15 of the 50 who also rode the 25, and halved them to compare against the gaps in the 25:
Rider 1: 3:56 unshaved, 2:50 shaved, swing = 1:06
Rider 2: 0:31.5 unshaved, -0:07 shaved, swing = 0:38.5
Rider 3: -0:22 unshaved, -0:32 shaved, swing = 0:10
Rider 4: -0:23 unshaved, -0:29 shaved, swing = 0:06
Rider 5: -0:24 unshaved, -0:47 shaved, swing = 0:23
Rider 6: -0:32 unshaved, -0:33 shaved, swing = 0:01
Rider 7: -0:46 unshaved, -1:10 shaved, swing = 0:24


So I performed better today relative to everyone in the top 15 who rode both events, with a swing ranging from 1 second to 66 seconds per 25 miles. The mean swing was 24 seconds.


My NP for the 25 mile TT was 7.4% higher than for the 50 mile TT, which I'd have thought would be reasonably average for relative power.


Obviously I'm not claiming this is particularly strong evidence, it was just something fairly simple to look at.
Last edited by: Steve Irwin: Jul 5, 14 14:58
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Re: Shaved Legs = 15 watts? [wbattaile] [ In reply to ]
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wbattaile wrote:
What he said ^^^

If CxA is aero drag then it looks like the tests ranged from around 2% to 7-8% drag reduction?
The reported numbers imply a reduction in both air and rolling resistance after shaving. Not sure how much Crr would really have changed, and normalizing for that would amplify apparent aero changes. So there's likely other things going on with the data. Environmental, positional, power measurement controls. As well as a real effect of course. Crr calcs can sometimes be pretty sensitive to minor measurement changes.
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Re: Shaved Legs = 15 watts? [Watt Matters] [ In reply to ]
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> air and rolling resistance after shaving.

OK, now someone do an FTP test after shaving. I bet it increases FTP by another 15W.
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Re: Shaved Legs = 15 watts? [themadcyclist] [ In reply to ]
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There's no such thing as "Free Speed". Or "free lunch".
It's called "opportunity cost" in economics.

Shaving takes time and commitment. Once you commit you have to keep doing it, regularly. It itches. You get ingrown hairs.
All this time and effort can be put to other things. Like training. Or family time. Or work.

Therefore it matters whether the savings are 7%, as Specialized claims. Or if it's 0.6% as previous research indicates. Or maybe less.

Frankly, the 7% numbers seem way high to me. Many of us have a gut feeling for what 7% in drag or power savings feels like. So it's 7% for shaving legs, probably another 5% for shaving arms. Really?! That doesn't sound wrong to anyone? Think about it. To save 7% on the climb you need to lose like 14 lbs. But shaving legs can do that for you in ITT?!

So then when riders who don't shave put on leg warmers they all of a sudden drop all others by huge margins - 7% and they never realized it? When Specialized testers found this amazing result, have they bothered to test leg warmers?

Extraordinary claims require extraordinary proof. I will wait till other labs reproduce the results but this doesn't pass a gut-check.
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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The "opportunity cost" of shaving? Seriously?

God this place is ridiculous sometimes.

I've never shaved either. Not a fan of the idea. But rather than waiting for sixteen peer-reviewed, double-blind, wind-tunnel tests, I'lll probably just try it and do a few TTs that I've done without saving and see what happens. One or two aren't enough but in the aggregate, it shouldn't be that hard to see if there's actually a significant savings.
Last edited by: JoeO: Jul 16, 14 19:42
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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53x11 wrote:
Once you commit you have to keep doing it, regularly.

Why? Why not just shave before races?
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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Unless you can "feel" the results of the Navier-Stokes Equations, I'll take measured data in a wind tunnel over what someone "feels"

Fluid flows are incredibly complex, and often times are counter intuitive. We may intuitively understand things like the motion of a projectile, but fluids are not intuitive, especially compressible flows like air moving around a moving rider.
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Re: Shaved Legs = 15 watts? [Anando] [ In reply to ]
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It all makes sense to me now. I always used to think any good race results I had were due to training and a moderate amount of talent.

Now I know it is simply due to the fact that my legs are naturally almost completely hairless. (We are talking about .01 on the Chewbacca scale. ) My wife envies me.

Not the best result in the genetic lottery, but at least I got something.
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Re: Shaved Legs = 15 watts? [helo guy] [ In reply to ]
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Re: Shaved Legs = 15 watts? [Anando] [ In reply to ]
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We all deal with Navier-Stokes every day when we ride our bikes. You don't need wind tunnels to tell you that when you tuck in behind another rider or when you are in the drops you have less drag. Or do you?

Sure, I will believe scientific results. But which ones? The ones that say leg hair is worth 0.6 percent, or the ones that say it is 7%?

What's really much more disturbing to me is that these tests are an order of magnitude off. How can we believe anything if for whatever reason (protocols, etc.) the same experiment comes off different by a factor of 10? Makes me question any wind tunnel tests. It's like if you go to one doctor and he says - you weigh 160 lbs. But then another one says - my super-precise scientific measurements say you weigh 1,600 lbs, yes, I was surprised too, but... science!

Would you trust any doctor after that?
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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53x11 wrote:
There's no such thing as "Free Speed". Or "free lunch".
It's called "opportunity cost" in economics.

The three minutes it takes me to shave from waist to ankles every couple days pays dividends from the GF, don't care what it does for speed or not.

Also I like looking at my legs.
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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53x11 wrote:
We all deal with Navier-Stokes every day when we ride our bikes. You don't need wind tunnels to tell you that when you tuck in behind another rider or when you are in the drops you have less drag. Or do you?

Sure, I will believe scientific results. But which ones? The ones that say leg hair is worth 0.6 percent, or the ones that say it is 7%?

What's really much more disturbing to me is that these tests are an order of magnitude off. How can we believe anything if for whatever reason (protocols, etc.) the same experiment comes off different by a factor of 10? Makes me question any wind tunnel tests. It's like if you go to one doctor and he says - you weigh 160 lbs. But then another one says - my super-precise scientific measurements say you weigh 1,600 lbs, yes, I was surprised too, but... science!

Would you trust any doctor after that?

All talk, and no game.

You don't evaluate studies based on results; you evaluate them on test protocol and methodology, and sample size. Hint: when you have a small base, ratios can be really big. And you're comparing gross measurements to to % change? And you think drafting and drops are only 7% decreases in total drag?

Do us all a favor and go back to figuring out the difference between "to" and "too" instead of trying to analyze studies.
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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53x11 wrote:
We all deal with Navier-Stokes every day when we ride our bikes. You don't need wind tunnels to tell you that when you tuck in behind another rider or when you are in the drops you have less drag. Or do you?

Key point is comparison. When you tuck behind a rider, you feel the difference. You compare somebody's wake to free-flowing air.

So until you start shaving mid-ride, this analogy doesn't really hold water.


And that's before we consider that 30% >> 1-7% and how imprecise we are in evaluating these changes based on feel.

ZONE3 - We Last Longer
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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"All this time and effort can be put to other things. Like training. Or family time. Or work."

..how long does it take you to shave? man I'll knock it out in 5minutes..enter in log as "Active Recovery"..

cheers
S.



// qui audet adipiscitur
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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53x11 wrote:
What's really much more disturbing to me is that these tests are an order of magnitude off. How can we believe anything if for whatever reason (protocols, etc.) the same experiment comes off different by a factor of 10? Makes me question any wind tunnel tests. It's like if you go to one doctor and he says - you weigh 160 lbs. But then another one says - my super-precise scientific measurements say you weigh 1,600 lbs, yes, I was surprised too, but... science!

Would you trust any doctor after that?

Well it is more like one doctor saying you weigh 146lbs and one saying you weigh 160lbs. (since you could weight 145 lbs and one measures a 1.6lbs change from baseline and another 16lbs from baseline). Still a large change, but not as big as you trying to convey.
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Re: Shaved Legs = 15 watts? [MOP_Mike] [ In reply to ]
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MOP_Mike wrote:
BMANX wrote:
What about going from very hairy and using an electric shaver to trim down but still having stubble and not doing the full shave. Thoughts.


That is a very good question.

I wonder if an optimum amount of stubble would trip the boundary layer like (dare I say it) wheel dimples...


EDIT: Then, there is this: http://www.slowtwitch.com/...erformance_4255.html

That article was posted on April 1......April Fools Day

Make Inside Out Sports your next online tri shop! http://www.insideoutsports.com/
Last edited by: BryanD: Jul 17, 14 7:51
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Re: Shaved Legs = 15 watts? [BryanD] [ In reply to ]
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BryanD wrote:
MOP_Mike wrote:
BMANX wrote:
What about going from very hairy and using an electric shaver to trim down but still having stubble and not doing the full shave. Thoughts.


That is a very good question.

I wonder if an optimum amount of stubble would trip the boundary layer like (dare I say it) wheel dimples...


EDIT: Then, there is this: http://www.slowtwitch.com/...erformance_4255.html


That article was posted on April 1......April Fools Day

You picked up on that, did you? ;-)


"100% of the people who confuse correlation and causation end up dying."
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Shaved for the first time this weekend - had my highest average speed for a tri. Obviously dozens of variables at play, but...

Aaron Bales
Lansing Triathlon Team
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Re: Shaved Legs = 15 watts? [MI_Mumps] [ In reply to ]
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I am so shaving for my next race.
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Re: Shaved Legs = 15 watts? [MI_Mumps] [ In reply to ]
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I've been riding slower and I attribute that to not shaving...
It's time to de-hair a bit.
Besides, feel much more athletic when I do. :D
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Re: Shaved Legs = 15 watts? [MI_Mumps] [ In reply to ]
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MI_Mumps wrote:
Shaved for the first time this weekend - had my highest average speed for a tri. Obviously dozens of variables at play, but...


Ditto. Shaved legs and arms. I'm probably a 7 on the Wookie scale. 22.4mph in an olympic on 197 watts. I was going to upload to BestBikeSplit and compare to a few other efforts when I have some time.

http://app.strava.com/activities/165503830

6'1" 175lbs. Setup below - seat a little lower/arms a little more stretched than when photo was taken based on ST advice (no dog in the race-day setup).



/kj

http://kjmcawesome.tumblr.com/
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Re: Shaved Legs = 15 watts? [spomeroy] [ In reply to ]
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Maybe the UCI will ban hairless legs given its apparent efficiency.

On a more serious note, I was told some years ago by a chap who knows a few things about aerodynamics that he'd always wanted to test the efficacy of shaving the front of the legs only. Therefore, leaving the rear or trailing edge of the legs hairy. I didn't take him seriously, but modern skinsuit technology seems to be working on the same principle, so maybe he wasn't joking.
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Re: Shaved Legs = 15 watts? [kjmcawesome] [ In reply to ]
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I think arms may happen for Nationals. Wife already hates the shaved leg look, might as well go all out...

Aaron Bales
Lansing Triathlon Team
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Re: Shaved Legs = 15 watts? [MI_Mumps] [ In reply to ]
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I just used clippers on the arms and the first pass of the legs. Used a blade for the part from my shorts to ankles.

Ingrown hairs are not sexy.

/kj

http://kjmcawesome.tumblr.com/
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Re: Shaved Legs = 15 watts? [kjmcawesome] [ In reply to ]
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Yup - that's what I did too (minus the arms). Definitely a process! No ingrown hairs though, thankfully.

Aaron Bales
Lansing Triathlon Team
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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I am beginning to think that if we add up all the claimed power savings from certain bike frames, tires, helmets, skin suits, and now shaved legs, that biking 40 kph is now power negative. I'll be able to expend -60 watts and go 40 kph.

________________
Adrian in Vancouver
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Re: Shaved Legs = 15 watts? [AJHull] [ In reply to ]
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AJHull wrote:
I am beginning to think that if we add up all the claimed power savings from certain bike frames, tires, helmets, skin suits, and now shaved legs, that biking 40 kph is now power negative. I'll be able to expend -60 watts and go 40 kph.

Just like golf clubs... every single year Titleist/Calloway/Taylor Made/etc. has a pro on the screen and states, "I hit it 10-15 yards farther". If that was at all true, we'd be hitting 450yard averages by now.
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Re: Shaved Legs = 15 watts? [53x11] [ In reply to ]
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53x11 wrote:
Many of us have a gut feeling for what 7% in drag or power savings feels like.

lol, no you don't. But I guess that "gut feeling" is a great way to justify buying aero anything. "Of course this was worth it, I feel faster". Ignorance is bliss.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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BrentwoodTriGuy wrote:
I feel like this whole thing should be written in pink because A) I'm being punked and am too stupid to know it or B) Jesse Thomas is being punked.

In the new Triathlete magazine, the hairy beast that is Jesse Thomas wrote that he did a shaved legs test at the "Win Tunnel" and they found he gained 15 watts by going shaved compared to full beast.

Am I missing something? It sure seems like I am.

Ok, we are many pages into this post and I still cannot figure it out. Is this a joke, a prank?
If so, will someone please tell us?
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Re: Shaved Legs = 15 watts? [chris948] [ In reply to ]
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yes I would. If you ride solo and don't pay attention to speed or power maybe you won't. But if you ride with others, or track your numbers, you know that 7% is a huge difference. Being dropped by 7%, or getting 7% fitter and being able to "catch" a guy 7% more powerful - this is huge.

You really can't tell when your performance drops off (or gains) by 7%? Seriously?
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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Thanks a bunch for this Mark... great stuff! Unfortunately I already shave my legs, so no free speed for me. I'll be interested in your arm shaving results...

Any thoughts on how this large decrease in drag makes sense? Seems that the legs are a pretty large part of total drag for starters. I already suspected this from Tour's tests with a torso-less dummy. They were getting drag values nearly as high as I'd expect from a full rider.
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Re: Shaved Legs = 15 watts? [rruff] [ In reply to ]
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Bringing the importance of legs to the fore, makes me start to wonder a bit more about the effect that stance width can have on your drag. Sorry if OT.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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Just finished 1st time shaving for some field testing this weekend. Anyone heading to Bracebridge this weekend, prepare to be dominated!

I'm (was) at least an 8 on the wookie metre, so I'm hoping to cash in on almost all of those 15 watts.

If I end up making this a regular look I'm gonna have to invest in an electric razor for the first pass. Seriously, that took a hell of a long time. After the first leg I was ready to call it quits and just live with half the gains. (Figured this may lead to some handling issues due to pressure differentials so for safety reasons I had to finish the job.)

This did bring up an interesting question though, exactly where do you stop once your near the top?
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Re: Shaved Legs = 15 watts? [MITaerobike] [ In reply to ]
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MITaerobike wrote:
Our tester who saved 50 secs had tall socks, low shorts (just above the knee), and had thin thin hair over the knee and upper lower legs.

That was a massive difference. I can confidently say that those with light leg hair thinking this doesn't apply to them need to believe this is as big of a difference as it is.

Arms we aren't very far on testing. We need a lot of data for this - TT and road positions will be very different. There's likely a difference but not as much as legs.

Mark

Pretty cool. Always done it because it's obvious it makes a difference in the pool and on the bike, but was surprised as well to see that much of a difference.

-Bryan Journey
Travel Blog | Training Blog | Facebook Page
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Re: Shaved Legs = 15 watts? [Dufflite] [ In reply to ]
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That's why the electric buzzer is key. Stop ar your ear lobes. Then just use the blade from anklesto thigh.

/kj

http://kjmcawesome.tumblr.com/
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Re: Shaved Legs = 15 watts? [Dufflite] [ In reply to ]
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On a related note...

Another debate has been the shave-down for pool swimmers. Again, no really great data. I've seen some reliable data that suggest that your rate of decay off the wall is lower, suggesting that there is less drag in the water. It makes the hypothesis of shaving is faster in the water plausible, but gains on a per/100m basis have not been outside of the margin of error when they actually test swimmers, but all those studies did a piss-poor job of setting up and testing (they also included the taper and speed suits).

So, in a pool triathlon, like the one I have tomorrow. I will not be tapered, and I will not be in a legit speed suit (just a basic tri suit). I may have to shave down...again not scientific due to only one data point, but it will be interesting to see if it makes a difference.

My predicted 750m time based on my current training will be 12:45 ± 0:15 (I don't have enough of a training/racing history to really know precisely where I'm at). So if I'm faster than 12:30 and don't feel like I'm swimming out of my mind, it'll offer more fuel to the fire.

Pertinent info:
I'm an 8 or 9 on the wookie scale, and usually have a fairly large beard too
I have swum for a little over 2 years
long intervals (400m+) in drag shorts are usually comfortably in 1:40/100m ish (short course)
I won't shave my arms (that's weird, and you kind of want your arms to 'grip' the water anyways right?)

I think slow-twitchers could probably come up with a swimming test protocol that could be fairly scientific and it would be really cool if we can put this to rest. Say 100-200 subjects doing a 400m time-trial at full wookie. Record RPE and time. Do 'normal training' for only a week (since you aren't going to get any real gains in fitness/form in a week), shave down, and do another 400 time-trial and record RPE and time. Tests must be performed in the exact same suit, goggles and cap. Base on data collected, we could even check how much of a difference there is if you are just wearing jammers, drag shorts, or a tri suit (there may be larger gains for difference attire).
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Re: Shaved Legs = 15 watts? [InWyo] [ In reply to ]
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As a former swimmer, I can attest that shaving down for the big meet does work. I'm sure there is some physical basis for it but there is also a huge and very real psychological effect. Its a ritual, often done in community with your teammates, and it only happens a couple times a year as a culmination of a taper for a big important meet.

It definitely works, but I'm not so sure we could not have gotten almost the same effect by ritually sacrificing a goat in the shower room the night before the big meet.

(Luckily no one thought of that because if someone had, we were definitely crazy enough to try it, of course only after we had shaved down ourselves then ritually shaved the goat).

So, whatever the test is, include a group who still has their hair but did something else to get themselves really amped up ;-)
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Re: Shaved Legs = 15 watts? [InWyo] [ In reply to ]
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Racing a sprint on Sunday and had the GF take the clippers to my legs last night. So I would say I am a 8 on the wookie scale as I used to shave my legs for a decade but I have not raced for the last 8 years so the hair has grown in very well.

I did a TT in the pool with full hair and in my race suit this week and did the 750m in 13:30 so it will be interesting on Sunday if my times have dropped. Also I am interested in seeing how my bike time goes since I did two TT on the race course over the last couple of weeks and I did 36:10 and 35:20 for the 20km course. the 36:10 was just after a rain and the 35:20 was on a dry day.

The GF was laughing at how much hair came off the legs and she insisted on vacuuming the floor after each leg because she said there was more hair on the floor from shaving my legs than there is after me getting a hair cut.

I forgot how different it feels with no hair on my legs.
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Re: Shaved Legs = 15 watts? [aaronechang] [ In reply to ]
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aaronechang wrote:
Why would someone test this before? Well at the beginning of the video one of them said that the shaved legs thing is one of the most frequent questions asked about aero, that's why.

Specialized is a bike / components company, and they just tested shaved vs. unshaved legs. You just answered your question "why would a bike company test this?" in your last sentence.

Wind tunnels have been around for a long, long time so I'm just wondering if there are any other studies / tests and if not, then why did it take so long. In fact you don't really need a wind tunnel to test this - people have been measuring the real-world effects of aero for quite a while outside of a wind tunnel using controlled roll down tests or riding around a track with a power meter. I even remember reading an experiment that Mark Cote did at Specialized using some Australian ProTour cyclist, a closed velodrome / track, and a power meter (I think it was to test effects of tri bike vs. road bike with aero bars, TT helmet vs aero helmet, and other stuff).

In short - since everyone has been debating this ad nauseum since the beginning of time, is this really the first test of shaved legs in a wind tunnel? If not - then how do the other studies compare?

Skipped most of the thread, so this may have already been addressed by the folks at Specialized, but here are a number of answers:

Point 1. I'm sure it has been tested at some point, by someone, prior to specialized. Olympic cyclists and TDF caliber athletes have been tested for details far less significant than the effects of surface texture of such a large area of their body.

So if it was tested before, why don't "we" know about it?

Point 2: First and foremost, wind tunnel test data is proprietary. The folks paying for the test own the data. Due to the enormous cost of obtaining this data, and competition-sensitive nature of the data (think: speed on the race track, being able to market production vehicle MPG/appearance), there is far greater value in keeping the data a secret and maintaining the competitive advantages than there is in releasing the data. The idea of releasing wind tunnel test data with competition-sensitive implications publicly (aside from the work of NASA/NACA or universities) probably didn't come about until fairly recently as "consumers" such as triathletes, motorsports hobbyists, etc. began shelling out the money for tunnel time, to obtain data that is of more value to them (as an individual) than to a competitor, or perhaps has some intrinsic value to the community that does not preclude the individual from obtaining a competitive advantage. Motorsports teams pay millions of dollars per year to book tunnel time, supply test assets and equipment, and to pay for engineers and staff to execute the tests, postprocess data, etc. The data collected influences whether or not teams win races, which is worth MANY millions of dollars per year. Giving away data is essentially financially damaging because it erodes the ROI on the tunnel testing investment. Basically: I believe that the phenomenon of people who expect no financial ROI on tunnel testing is relatively recent, and this expectation allows them to release data. Now, the way that cycling/triathlon goods producers have found a way, ostensibly to increase revenue, by releasing expensive data is interesting--by using the data to market the product to a niche group of well educated consumers, the producers are recouping their tunnel time investment by doing the exact opposite of what most commercial wind tunnel users do. But there are still people in cycling who need "wind tunnel secrets" to make money, namely professional cyclists. Why would a pro cyclist release their data, their drag-reduction ideas, or their proprietary equipment to their competition? If "shaved legs vs. hairy legs" was tested before, I suspect the data was not released for this very reason.

For some additional perspective:
Commercial wind tunnels (and their staff) by and large exist only to facilitate the test. The information privacy requirements dictate that the tunnel staff (who will see equipment/parts/pieces/data from multiple teams) do not share this information between teams, so they necessarily cannot be involved in making changes, evaluating data, etc. The tunnel staff are contractually bound to secrecy, and it is taken EXTREMELY seriously. They are simply there to man the ship. Customers bring their own staff to write the test plans and test sequences, make changes/adjustments throughout the test, and evaluate results). This is where A2 (and FASTER too, I guess, though I don't have firsthand experience there) bridge the gap between the "commercial wind tunnel" and the end consumer. Like it's "big brother" Aerodyn, A2 supplies an operator that will control the wind tunnel, but unlike its entirely commercially oriented counterpart, the A2 operator also fulfills somewhat of the role of data collector/analyst, and has historically employed a person experienced with aerodynamic bike fitting to help with changes.

__________________________

I tweet!

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Re: Shaved Legs = 15 watts? [ZackCapets] [ In reply to ]
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ZackCapets wrote:
aaronechang wrote:
Why would someone test this before?

Point 1. I'm sure it has been tested at some point, by someone, prior to specialized. Olympic cyclists and TDF caliber athletes have been tested for details far less significant than the effects of surface texture of such a large area of their body.

So if it was tested before, why don't "we" know about it?

When was the last TdF/pro/elite/Olympic cyclist you saw race that had hairy legs?

IOW what incentive is there to test when everyone's legs are already the same hairless state?
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Re: Shaved Legs = 15 watts? [Watt Matters] [ In reply to ]
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People have been biking for a lot longer than I have been alive...

__________________________

I tweet!

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Re: Shaved Legs = 15 watts? [ZackCapets] [ In reply to ]
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Specialized did the testing in their own wind tunnel - sounds like the test was done on a lark and the engineers were extremely surprised at the results so shared it with the rest of the world. Look in the first few posts for the details and link to video on testing protocol.
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Re: Shaved Legs = 15 watts? [BMANX] [ In reply to ]
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Well...

Raced my sprint last week shaved. Expected a swim split of 12:45, and had a swim split of 12:00, and it felt quite easy.

possible other contributing factors:
  1. My predicted time was based on my performance last year and training done in drag shorts.
  2. Flip Turns! I usually struggle with them, but in 750 short course meters, I only open turned 3 times
  3. Favorable land draw: I was placed right next to a guy that is usually just a tiny bit faster than I. Swam just behind him for 10 laps before I pulled ahead of him, and ultimately pulled away from him, but I may have had a draft for the first part of the race (we were seeded 2/lane so we were both right next to the rope).

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Re: Shaved Legs = 15 watts? [InWyo] [ In reply to ]
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My race went well for the swim and bike. I was 30 seconds faster than I had swam in practice for the 750m short course. There were 8 per lane and I was the 6th person. Swam the first 100m and was in first position then two passed me at the wall as it was a bit of controlled chaos. We then swam like that for the rest of the distance. That was the fastest 750m I have done all year.

Passed 10-12 people in transition. Glasses, helmet, bike and gone.

The bike was 2 full minutes faster then the two times I had ridden the course before the race. I was not expecting to ride that quickly. I did however over-cook the bike which bit me in the ass on the run.

In training I did the distance on the course twice and pushed it as much as I could but with full hair on the legs. I was wearing my aero helmet on race day, fully shaved and wearing my Sugoi Velocity II Tri Suit. Not sure which contributed the most.
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Re: Shaved Legs = 15 watts? [BMANX] [ In reply to ]
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This came up recently in a web article:

http://www.theglobeandmail.com/life/health-and-fitness/health/the-curious-case-of-the-cyclists-unshaved-legs/article20370814/


Slowtwitch was referenced - any more anecdotal results to share?


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Re: Shaved Legs = 15 watts? [Khyron] [ In reply to ]
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Re: Shaved Legs = 15 watts? [Staz] [ In reply to ]
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Perhaps we all need to shave a cute little Mohawk into the trailing edge of our legs and arms. It will help the flows rejoin and save another five watts...

Could be a great design of experiments to see how wide the Mohawk needs to be verse your ranking on Sasquatch scale.

Not sure if this should be pink or not.
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Re: Shaved Legs = 15 watts? [AEllswrt93] [ In reply to ]
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AEllswrt93 wrote:
Perhaps we all need to shave a cute little Mohawk into the trailing edge of our legs and arms. It will help the flows rejoin and save another five watts...


Could be a great design of experiments to see how wide the Mohawk needs to be verse your ranking on Sasquatch scale.

Not sure if this should be pink or not.


Boy, do I have just the thing for you.

http://www.slowtwitch.com/...erformance_4255.html
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Re: Shaved Legs = 15 watts? [Staz] [ In reply to ]
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Glad I was not the only one thinking pink.
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Re: Shaved Legs = 15 watts? [BrentwoodTriGuy] [ In reply to ]
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too true
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Re: Shaved Legs = 15 watts? [Khyron] [ In reply to ]
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Re: Shaved Legs = 15 watts? [sharkbait_au] [ In reply to ]
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It says "A newspaper in the States is reporting". WTF!? It's pretty clearly a Canadian newspaper. Even the logo is a Maple Leaf. But at least they're reporting that someone else is reporting on it, weeks after a bunch of people reported on it. Nice effort.
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Re: Shaved Legs = 15 watts? [Durhamskier] [ In reply to ]
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Lol. I didn't even read it, just mindlessly pasted the link.
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Re: Shaved Legs = 15 watts? [ZackCapets] [ In reply to ]
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ZackCapets wrote:

Skipped most of the thread, so this may have already been addressed by the folks at Specialized, but here are a number of answers:

Point 1. I'm sure it has been tested at some point, by someone, prior to specialized. Olympic cyclists and TDF caliber athletes have been tested for details far less significant than the effects of surface texture of such a large area of their body.

So if it was tested before, why don't "we" know about it?

You should read the thread. There is discussion on previous testing/papers and John Cobb himself even comments.

ZackCapets wrote:
Point 2: First and foremost, wind tunnel test data is proprietary. The folks paying for the test own the data. Due to the enormous cost of obtaining this data, and competition-sensitive nature of the data (think: speed on the race track, being able to market production vehicle MPG/appearance), there is far greater value in keeping the data a secret and maintaining the competitive advantages than there is in releasing the data. The idea of releasing wind tunnel test data with competition-sensitive implications publicly (aside from the work of NASA/NACA or universities) probably didn't come about until fairly recently as "consumers" such as triathletes, motorsports hobbyists, etc. began shelling out the money for tunnel time, to obtain data that is of more value to them (as an individual) than to a competitor, or perhaps has some intrinsic value to the community that does not preclude the individual from obtaining a competitive advantage. Motorsports teams pay millions of dollars per year to book tunnel time, supply test assets and equipment, and to pay for engineers and staff to execute the tests, postprocess data, etc. The data collected influences whether or not teams win races, which is worth MANY millions of dollars per year. Giving away data is essentially financially damaging because it erodes the ROI on the tunnel testing investment. Basically: I believe that the phenomenon of people who expect no financial ROI on tunnel testing is relatively recent, and this expectation allows them to release data. Now, the way that cycling/triathlon goods producers have found a way, ostensibly to increase revenue, by releasing expensive data is interesting--by using the data to market the product to a niche group of well educated consumers, the producers are recouping their tunnel time investment by doing the exact opposite of what most commercial wind tunnel users do. But there are still people in cycling who need "wind tunnel secrets" to make money, namely professional cyclists. Why would a pro cyclist release their data, their drag-reduction ideas, or their proprietary equipment to their competition? If "shaved legs vs. hairy legs" was tested before, I suspect the data was not released for this very reason.

For some additional perspective:
Commercial wind tunnels (and their staff) by and large exist only to facilitate the test. The information privacy requirements dictate that the tunnel staff (who will see equipment/parts/pieces/data from multiple teams) do not share this information between teams, so they necessarily cannot be involved in making changes, evaluating data, etc. The tunnel staff are contractually bound to secrecy, and it is taken EXTREMELY seriously. They are simply there to man the ship. Customers bring their own staff to write the test plans and test sequences, make changes/adjustments throughout the test, and evaluate results). This is where A2 (and FASTER too, I guess, though I don't have firsthand experience there) bridge the gap between the "commercial wind tunnel" and the end consumer. Like it's "big brother" Aerodyn, A2 supplies an operator that will control the wind tunnel, but unlike its entirely commercially oriented counterpart, the A2 operator also fulfills somewhat of the role of data collector/analyst, and has historically employed a person experienced with aerodynamic bike fitting to help with changes.

I'm not really sure what your point is here. I see this exercise as marketing and relations building. Specialized is giving out free information, while promoting their products, to build good will and trust. They own their wind tunnel so the majority of their costs for producing this data are already sunk.
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Re: Shaved Legs = 15 watts? [Pantelones] [ In reply to ]
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The "free" speed on the bike and in the pool are nice things, but for me they are additional bonus's on top of the real reason why I shave the legs:
I am notoriously bad at heat-dissipation (I did a 5hr20' at 70.3 IM St-Croix in 2013, 2hr05 for the 1/2 marathon ....) and for me the biggest advantage of shaving is heat-dissipation.

The removal of all hair from legs, chest and armpits (I'd rate myself a 5 on the wookie-scale) makes me feel better during races (especially during the run) and it helped me to already secure a IM70.3 WC slot for next year. I did similar race-training as last year, yet continously run at target pace during races whilst other races, I start at target-pace and within 30-45 min, the wheels start coming off due to overheating.

This is how bad I can handle the heat:
On a indoor-training ride, I can easily loose >1ltr of sweat /hr....
Running outdoors in sunny weather with temp of 15-17°C is a high as I can tolerate in the sun without pace or HR suffering badly. When it is overcast, I can tolerate up to 20-22°C. Anything temperatures higher then that and my heart-rate jumps up by >10bpm for same pace and soon thereafter the pace drops and the heart-rate remains level. I guess I am not genetically programmed to perform well at Kona but more for Norseman ;)

I consider myself fairly lean: 1m79 and 68kg (9% BF, measured by scanner 2,5 weeks ago when I was at 69kg)

S.

ps: Another bonus for shaving is that I can finally see the real tuned and hard-earned shape of my calfs and quads on my twig-sized legs ;)
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