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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. 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!

:)
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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

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

Aaron Bales
Lansing Triathlon Team
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Re: Shaved Legs = 15 watts? [noofus] [ In reply to ]
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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.
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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.

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
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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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