Do you mean why you can't? Because in that case I agree completely.

In general I agree with what they say (here and elsewhere), I love their videos, but I don't like them perpetuating the myth that the aerp bike is less comfortable and using the heavier wheels as a negative point is bull as wheels can obviously be changed out.

Edit: For clarity.

What a poor piece of journalism from two so-called experts. Where to begin...

"But the fact is though, that your average speed if you get home from a normal ride on a Sunday is 26 km/h, actually, you're not really going to see any benefits from riding an aero bike, except for one or two exceptions on your ride."


Yes, because everyone knows that aero doesn't 'kick in' until you hit 40 km/h...


"Let's talk about comfort as well. Aero bikes have always had a bit of rep for being slightly harsher than a lightweight bike. I mean, they're also ironically enough flexier because they're narrower in their frontal profile so you don't get that kind of torsional rigidity."

The recent ST feature Thoughts on science & perception is a good read related to this topic. Josh Poertner was involved in blind bike tests with experienced cyclists. He writes:

"One of the major discoveries was that after controlling for seat post (round post shimmed into aero frame so as to not give it away) not a single rider found the aero road bike to be less comfortable, less compliant, etc, than the identically setup 'endurance' or 'roubaix' bike."

BMANX wrote:

Still do not understand why you can't have a light aero bike for everything but that is just me.

Because the industry wouldn't sell as many bikes. The industry has a vested interest in perpetuating myths that compel people to own multiple bikes.

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CodyBeals.com | Instagram | TikTok
ASICS | Ventum | Martin's | HED | VARLO | Shimano | 4iiii | Keystone Communications

Weight is never a consideration in my cycling gear choices.

Same here. ;)

I don't see the point of an aero road bike. Most of the drag is made from your body so if you're in the same body position on the regular light and the aero it wouldn't be significantly different like what 10 watts at most difference on flat polly. I would own a tt bike for being aero and a light one for being light. If I had to pick one I would go tt because I love them they are heavenly like soooo comfy slippin thru that air at mach 3. Instead of buying 1 high end aero road I'd get a tt and road carbon 105 + get them the hoops they deserve eventually. I've never ridden a super high end bike tho so idk what I'm missing out on but polly not that much. I totally ignored their data cause it wasn't accurate. They had different wheels, bodies, gear etc wasn't based on frame dynamics

Did you actually watch the video? They did two runs each and setup the bikes the same for position. Sure it's far from a scientific test but they got similar results for the two of them. 110m farther over 10 mins is not insignificant.

10 watts is an astronomically huge amount.

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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

Almost 4 minutes faster over 40km if you go by their testing. Ya not that important really and who really wants to finish their 40km ride 4 minutes faster.

One of the guys in the video, Daniel Lloyd, is about the most aero-enthusiastic pro bike racer that has ever been. He took part in the development of the S5.


So sorts puts into context the kinds of things your average pro bike racer believes.

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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

You know aero bikes are uncomfortable and heavy. Oh and their head tubes are lower as well.

Had a good laugh at you calling them out in the YouTube comments and subsequent tweet to Dan. QFT:

"summary: "we viscerally hate aero bikes so even though we weren't able to prevent them from being faster in our bs test, here is a lot of totally false received wisdom we can use to trash talk them anyway"

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CodyBeals.com | Instagram | TikTok
ASICS | Ventum | Martin's | HED | VARLO | Shimano | 4iiii | Keystone Communications

I stole that quote from a friend, thought it was funny.
Didn't realize Daniell Lloyd was one of the guys. Now feel like asshole.

TOO BAD HE SPOKE ILL OF AERO

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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

Being fast doesn't excuse broscience. IMO, it makes it even less excusable.

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CodyBeals.com | Instagram | TikTok
ASICS | Ventum | Martin's | HED | VARLO | Shimano | 4iiii | Keystone Communications

No don't bring attention to us!

Yea they had different helmets, body weight, body shape, one had deep sections, polly had different wind conditions and slightly different power as well too. A single 10 minute trial of 2 riders from using different gear isn't enough data to draw accurate conclusions about the frames polly. If you have to do the minimum weight then I see the point of aero road but I can tell the difference of carrying extra water etc. Granted it's negligible compared to drag but the frame itself probably isn't making that much drag and a few pounds saved might be better in a lot of conditions. Idk tho I'd need more data to draw conclusions but I'm skeptical of aero road considering they're not that aero

They both rode each bike once. Even without this test there have been tons of previous tests. And a few grams of drag make much more difference than weight in every situation other than going uphill. Once you get up to speed on the flat weight essentially becomes irrelevant, it only plays a role in acceleration.

Well if you read most of those replies you will see that people just do not get aero. Maybe 5% of the people posting in the comments section under that video actually get it.

I will always go with aero and light as it kills two birds with one stone. A 13 lbs aero and light bike is just the best of both worlds and only leaves on thing to worry about and that is the rider. So now I have to do a lot more work there.

The one comment that I liked was the one guy that said an over-weight cyclist will not benefit from an aero bike.

Yes i understand aerodynamics are very important. You are probably making a million grams of drag by pulling your body out of a tt position. I would rather have a 10lb road than a 13lb aero road. Maybe get a 10lb road and throw tt cockpit on it for a real "aero" road

You clearly do not get it.

Oh my God what did I just read.

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I'm on a guest computer and I made the effort to log on and like this post.

Sorry bro, if you are interested in a 10lb road bike you have no excuse to not acknowledge the significance of an aero bike. No matter how much light they are making stock parts these days it's gonna take some cash to get down to 10lbs.

Nice video but who cares about aero bikes vs. climbing bikes when you can ride the Varibike?
http://www.dailymail.co.uk/...html#v-2646076558001

Lol I know i don't get it. Isn't the point of riding your road bike for the hills? aero road bikes make no sense to me because they're not very aero. I want a tt bike for when being aero is an advantage and a road bike for when being light is an advantage. I understand if you're a pro and have minimum weight cause you have to have the weight. A 13lb aero road would probably be a similar amount of money. Like honestly the frame doesn't make as much drag as your body does extensions and base bar would be more aero and lighter if you really are making an aero road

Do you know what an aero bike is?

The point is to have a road bike with aerodynamic features when a TT bike isn't allowed or in situations where you want the best of both worlds. An aero bike is a more aerodynamic road bike and it can weigh as little as any other bike. Same weight + more aerodynamic = better.

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I sincerely hope people think just like you do. I will continue to ride my Felt AR ... see you at the finish.

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"4 wheels move the body, 2 wheels move the soul"

Lets just hope others do not see the new position studies done where riding the hoods is faster than riding the drops. But then again I know someone on this thread that would disagree with that as well.

Ride Faster Instantly

Yeah...but did you see that drops position with the straight locked arms? Oy vey...

My take on that test is it was a good argument for generally higher bars (so arms are bent in the drops with same torso position).

"Bend your arms, dammit!" ;-)

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http://bikeblather.blogspot.com/

If the center position in the top picture counts as "in the drops" then sure. Based on my n=1 I'd say the proper way to do so would also be with your elbows more bent and that position should be at least about equal to bent elbows on the hoods.

Beat me to it. Exactly.

And downhill.

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- I do all my own stunts

You got me.

I agree with you 100% and was thinking the same thing when I read the article. If you could use the drops with the horizontal arm position that would be better. Now put that position on a bike that is aero and you are doing better than a bike that is not aero.

Plus, with an aero road bar ;-) ...of course, it would also help if someone made an aero road bar with a "standard drop". All this compact drop stuff is maddening :-/

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http://bikeblather.blogspot.com/

compact drop is cool if you're 5'8, and a 51cm size bike looks much better if the drops don't overlap the front wheel. aesthetics are important :-)

I would think that the 0.4 kph difference in favor of the "aero bike" could be attributed to the wheels. The test would then indicate that there is no difference between the two framesets.

If you take into account how un aero standard bike frames are - some have incredibly fat tubes which make the bike less aero than a 1960s / 1980s steel frame - then the savings of an aero frame are a must. I have seen a test where an old steel frame was compared to an aero frame in a wind tunnel, same wheels same position, and the aero frame was about a minute faster over 40k than the steel frame. Now think how a fat carbon non aero frame would be even slower than the thin steel frame.

I will try to find the link.

When you get to my age you realise that bike frames have been getting stiffer particularly around the bottom bracket by about 5% every year since about 1970. Those old steel bikes must have been incredibly floppy.

The tyre pressure and position on the bike is what you can feel on a bike more than anything else.

Here is the link.

Same rider same wheels.

Watch it then think how un aero a fat tubed non aero frame must be.


http://m.youtube.com/watch?v=XE_GKePa3CQ

A lot of the difference could be from the fork and handlebars...

I'm not the resident expert, but I think what you are missing is that a, say, 16 pound aero road bike will almost always be faster than a 13 pound non-aero road bike, -including- on courses that have lots of hills. And the same applies to wheels, heavier aero is faster than shallow light weight wheels. The weight just doesn't matter as much as marketing would lead you to believe.

Even Cervelo used to have a write-up on their sit a while back explaining that their heavier aero road bike was always faster than their more expensive super light non-aero frames, except for situations like time trialing up Alp D'huez, etc.
Cheers

little bit here, little bit there.
grab ALL THE BITS

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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

Thanks for sharing.

I remember seeing someone on this forum, possibly Damon Rinard, saying that some of the new non-aero bikes, including one from Giant I think, tested among the slowest bikes they ever tested. Really I don't understand why not have an aero bike especially if it is equivalent weight. I know Canyon for example makes their Aeroad bike ranging from just above to just below 7 kg, including aero wheels, so with "climbing wheels" the bikes would weigh the same as any of the uci legal "climbing bikes".

With the UCI you have a minimum weight a bike can weigh. If you can only get a bike down to 6800g then why not have the most aero 6800g bike that you can have. For those that do not have to follow such rules, then you can still have a bike that is lighter and aero. I thought the article was funny because these days, a "climbing bike" and a "light bike" CAN be the same bike.

There are a lot of options out there right now for AERO bikes that could be built up very light. I do not even have the lightest version of SLC that Cervelo made so moving to the lighter version frame, changing out my wheels for tubulars and making some lighter component changes that moves the bike into the 11 lbs range. I am sure that would classify the bike in regards to weight as a climbing bike. Then you still have to cheat the wind as much as possible until you hit the tipping point while climbing. You still have to get to the climb as fast as possible and you still have to go down the backside (unless you finish at the top).

Specialized did a test on positions for descending and they found that there was a 7-8 kph difference in position choices and couple that with descending on an aero bike vs a non aero bike and you could have the difference of close to 10 kph. So if I descend on an aero road bike in the most aero tuck position I can be dong 80 kph instead of 70 kph which I am more than happy with.

This. Exactly my thoughts.

There we go...that's more like it. I think I would need to try those down sloping tops sections though to see if that would work for me...

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http://bikeblather.blogspot.com/

Why not? Well, for a LOT of people, pros included, their perception is that aero bikes just aren't light enough, are too stiff in the rear! and too flexy torsionally. I'm convinced that most of those perceptions are actually just visual. People are funny...


Taylor Phinney says "Hello" to you from Santa Barabara ;-)

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http://bikeblather.blogspot.com/

Hi Richard,

Exactly. Since the days of steel frames, bikes have gotten both better ... and worse!

Cheers,

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

I am convinced that an aero bike will be faster- for climbing and everything else.
Just need to find the right aero bike.
If the S5 turns out to ride as nicely as the S3 (old S5 did not), I will get an S5.
If not, I will get an S3.
I am actually hoping for the S5 as the new geometry will fit me better than current S3 geometry.
Damon? Any idea how the S5 and S3 stack up in terms of ride quality?
Either way I will be riding faster-

Save your cash, and lose 5lbs of body weight... or 10lbs... or 15lbs...

Hi bootsie,

I have not yet ridden an S5, but the lab numbers point to very similar ride feel as the new S3. Quite a bit stiffer torsionally, and handles very very well.

Cheers,

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

That's all else being equal though. If you chose bad lines, the aero bike won't save you.

But even if you lack good navigation, the testicular fortitude and bike handling skills to brave that speed and control the bike...you'll still go faster on the flats or climbing.

There are other factors besides aero and weight. Fit and Stiffness are also pretty important. Going from a flexy bike to a stiff bike was a big change in watts; maybe 10-15?

People talk about aero frames all day but in races and hammerfests 95% of the pack is riding on the hoods with an almost horizontal back. Because my bike fits and I ride in the drops with bent elbows I'll take my low profile vertical back over an aero bike any day of the week. Could I have both? Possibly but I would have to sacrifice riding a bike that didn't quite fit they way I like. I may get used to it but after riding a bike that did fit for two years I'm a stickler about it down to the centimeter.

Why don't you fit all aero frames? If you found an aero bike that fit like your current frame guess what, you would be faster.

I went from a Cannondale SuperSix (non-evo) to a Giant Propel. Both bike feel incredibly stiff (and very nice), but the Propel is faster on descents to a surprisingly degree. Once I got used to the extra push from cross winds, I haven't seen a single disadvantage of my aero road bike (though I race crits more often than road races).

Can you point to any testing confirming stiffness results in more power at the wheel and therefore more speed?

Lots of aero testing confirms the benefits, never seen the same for stiffness.

I recently switched my road riding from a 10 year old Kestrel Talon (aero, ~17.5 lbs) to a Domane Classics with all the bells and whistles (non-aero, 15.5 lbs). When I got done fitting my Domane, I ended up with the exact same 10 cm saddle-to-bar drop and reach I had on my Talon (Talon put me over the front wheel more though). Comparing files from solo training rides, I definitely got more mph per watt on the Talon, but for some reason my ftp is 10-15 watts greater on the Domane. It's a different power meter, so that could be part of it, or maybe it's just the fit, or maybe I'm just getting stronger at the end of the season.

The Domane is definitely more comfortable (duh), and if a race featured lots of pack riding and rough roads, I think the comfort/sprint stiffness would win out. I have to say though, it is a little amazing how well the 10 year old cheap azz Talon has held up against modern offerings-- an aero road bike before it's time!

It is an interesting discussion...and with so much "kamm-tail" techno-marketing jargon...it's hard to tell fact from fiction.

I had two Scott Foil Aero Road bikes...a Foil 20 (pretty flexible bike in all the wrong ways) and a much much better Foil Team Issue. Both Foils fell victim to car crashes that were not my fault. So...having invested in a P5 for triathlon, I decided to give the Scott Addict Team Issue a try instead of the Foil.

The Addict feels a lot better and my Strava KOM segments are getting faster, but I think that's more the rider than the bike. But...on the rare flats when I ride the Addict I can "feel" it sucking energy! (Same geometry and exact same fit between Foil and Addict)

BUT....a friend of mine in the industry showed me his CFD simulations that highly suggest the Foil tube profile is WORSE than round tubes....and the Addict is essentially thin round tubes. But...until there is a more standard way of analyzing aero bikes...as consumers we are shooting in the dark. Though I highly respect Cervelo's reputation for aero-prowess....and given my P5...I would certainly be looking that way again if/when I need another road bike.

Also....can anyone comment on weight? Yes, I ride a frame/fork that is less than 1kg...but I didn't buy it because of its mass. My question is this....is 1kg on the frame similar to 1kg on the rider in terms of its impact? I assume it is. And in case of the argument, but the rider can always lose that kg and the bike is the bike so it's better if it is lighter...my BMI is 19 and body fat is 5.8% and if I still want to swim fast....I need all the KGs I have now!

Nope. Any sort of modern aero bike will not be losing more than a single watt to frame flex.

0 watts

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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

yes, and is the same as 1kg of wheels (to very very close approximation)

and if it isn't mountainous, that 1kg will have very little impact.

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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

This is only true if losing 1kg of rider does not have a negative impact on rider power output. In reality, most people lose a little power when they lose weight. I know it is very minor, but the assumption that you can just lob off a chunk of fat with no impact on the rest of your body is an oversimplification, especially as a rider approaches the lower limits of leanness.

I don't think that is usually the case in reality.
I think most people lose some power while at a calorie deficit and then give up.

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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

"inconsequential", sure. Zero watts? I doubt it. The business of a frame being a spring always gets trotted out--but before you bring it up as well, do you really believe that *all* of the power lost due to flex is returned in a way that provides forward propulsion? That seems unreasonable. I'm willing to bet that the differences are within the measurement error of power meters; otherwise, you could reliably test this by concurrently using a crank based meter and hub based meter. No one has demonstrated this yet (that's I've seen), so I'm guessing the difference is less than 2%. But it doesn't mean that it doesn't exist. I don't think 10-15 watts (1%) at peak power is actually that unreasonable, but that's a total guess.

Hell, I could even see that frame flex could impact Crr in extreme circumstances (like standing and sprinting or climbing). Doesn't mean I won't ride an aero bike, as what ever differences that exists are certainly overshadowed by aerodynamics, but I wouldn't completely ignore the possibility that frame stiffness may impact efficiency.

That, I could see as being a much more plausible thing, and it would be fascinating to investigate it.

People have put crank and hub power meters on bikes to try and measure power loss due to frame flex and can't find it.

Which suggests the difference is sub 2 watts during an all out sprint at worst.

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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

I'm not sure that's what it means. I've never seen .2% agreement between power meters, and I've spent a lot of time using an SRM and PT at the same time. I think it just means the difference is 1% or less.

You would expect the delta to change as a function of torque, or power though.

I suppose ultimately if you wanted to get at the ultimate answer - "what is faster" you take an S5 and an R5 and do many sprint repeats and plots the speed/power relationships.

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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

Your friend might want to work on his CFD skills...


There ARE standard ways of evaluating them: wind tunnels and field testing with power meters.


No you don't ;-)

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http://bikeblather.blogspot.com/

I may be misinterpreting this, but are you saying losing 1 lb of body weight is the same as losing 1 lb of bike weight?

Well, technically the top of the line Addict SL is marketed as sub 1kg for the frame and fork, but I haven't seen any independent claims confirming this. Seeing as this guy's Foil 20 is 80g over claimed, I doubt that the SL is sub 1kg.

If I was doing a solo TT effort, I would pick the aero road bike unless it's ridiculously steep. If I was drafting off of a semi (no air flowing over me or my bike) the entire race, I'd pick the lightest bike possible if there was any climbing involved. On the spectrum of solo TT effort to drafting off of a semi, where does sitting in the middle of the pack sit? If I were to gain 15W in a solo effort with an aero road bike over a non-aero one, how much would I expect to gain if I sit in the pack the whole time?

You still gain an advantage even sitting in a pack on an aero frame road bike.

Yes people with PhD's in engineering are all dumb which extends to standard CFD software that has been verified in wind tunnels too. Clearly they are clueless! Having seen the data myself there are many reasons many aero bikes are not aero. It is one of the advantages of living in Taiwan where people design and build bikes instead of just marketing them and putting on pretty stickers!

As for a Scott addict size 54 frame and for not weighing less than a kg...I have no idea why you dispute that... I've weighed my own frame and the data from Scott all indicate this. Seems simple enough!

as far as how fast you ride your bike, yes.

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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

The scott addict is about as aero as the foil because the addict was subtly shaped to be aero as well, the tubes aren't round.

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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

I don't know if you have ever done a bike race, I've done a couple hundred and every single one of them has moments where riding in the pack is hard. Lots of such moments. The reason it is hard in those moments is because of air.

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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

And yet, there are wind tunnel tests that show your buddy apparently did something wrong in his modeling:



You said "frame/fork that is less than 1kg", which means together...I highly doubt that together the frame and fork weigh less than 1 kg.

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http://bikeblather.blogspot.com/

You're right, for the same amount of effort on a flat section, it's the same aero drag whether I'm drafting or not. My speed will just be different.

Going with this, how does pack riding change the proportion of what each component contributes to the aero drag? I'd almost think that pack riding would make an aero bike give you more savings since your body is better shielded by other riders than your frame is shielded by other frames.

I think his buddy probably tried toe explain to him how they were able to use CFD to make the addict as aero as the foil while using more normal looking tubes, perhaps tubes with better stiffness/comfort/weight properties.

He has then taken this to believe that his roundish tube bike is faster than an S5/propel or something =)

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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

CFD is only as good as the model design and parameters used, and of course the operator.

GIGO still applies, even to software used by a PhD.

Hey guys...

OK...frame and fork weight on the Scott Addict team issue in my size...claimed 790/300...so yes, over the 1kg mark. And I checked my actual frame and fork that we weighed before assembling the bike...it was 1060g...but included the mounting brackets for the drive train and the headset parts were installed...so we are arguing about grams for this or that side of the 1kg mark....my point was simply that I do agree aero is more important than weight...even though I bought a light frame...and my total bike weight comes in at about 6.5kg with only very average wheels in terms of weight. (Fulcrum Racing 3...it's my training bike after all!)

As for the aero data.....I thank you for publishing the chart as I can use this next time against him! I want to be clear, however, he was not comparing the addict tube profile to the foil's. He was comparing Foil's truncated cam to a traditional round tube and arguing the round tube was actually more efficient than the Foil profile. I too found this unbelievable and still do fully trust it. What I am saying, however, is there are numerous ways to generate data about the aerodynamic performance of a bike and that creates all kinds of room for marketing spin. For example, some frames perform better than another frame at a certain yaw angle, but worse at others. In these cases, the answer to which frame is more aero is...it depends on the yaw angle. So there is no black and white...and that's where even honest differences in the science can lead to marketing hyperbole instead of honest insight into the performance of a frame.

Here is a short youtube video that shows the CDF findings; you can see from the shapes which tube profile belongs to which aero design and the truncated designs create far more turbulent air than the full profile tubes they are modelled on. I'm putting this out there for conversation and interesting debate...not to prove I'm right or someone's wrong. I just ride bikes fast...not design fast bikes....and when it comes to riding fast...the rider still makes more of a difference than the frame!


"//http://www.youtube.com/...xi7t5lSBgS7i3vGS1BgQ"

Then why is everyone so obsessed with saving a few grams here and there on their bike? Serious question.

Because eating is fun and people aren't good at physics?
Or they live around mountains.

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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

Welcome to slowtwitch Darren.

Not everyone here is new to this and is just assuming certain marketing claims are true.

Some people here have been to the wind tunnel themselves, or done their own field testing using clever methods like the Chung Method. Tom A has done both. Others like Andy F have invented amazing tools like the Alphamantis Track Aero system that Trek used to help Jens break the hour record.

There is quite a wealth of experience here, please do enjoy it!

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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

Thanks Jack!

I don't usually post so much but have a technical background, passion for tri, and the pleasure of knowing bike engineers and designers. I find they muddy the waters about as much as the marketing types!

I wish I could identify the quantitative factors behind my strong and clear preference for my addict over my foi . Both are made of the same carbon in the same Giant factory in Taichung. But the addict speaks to me in ways on climbs that my foil never could and makes my p5 seem a Jon not a pleasure. (But a fast job!) .And I suppose its those individual preferences that will keep the bike market diverse and strong.

I watched it.

I don't see a foil shape that matches the bike.

Shape matters a lot.

Anything to back up this Jack?

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http://cds-0.blogspot.com

I remember digging around on this a lot, found a couple people who had done tests with power meters at the hub and crank and found no discernable difference. Also found a post where Damon Rinard said they had tested the flexiest frame they could find and got the same results. Resulting conclusion was that if there was a difference it was within the error of the powermeters.

There is a question (for me) of whether the flexiest and the stiffest frameset out there will affect how much power you can generate, and if it will affect handling. Also worth noting that at this point in time frames are so stiff that a 15% increase in stiffness is the difference between 4mm and 3.6mm of deflection. The result is still super stiff.

(Upfront notice here, team is sponsored by Scott) As for the debate about foil/addict. They do come into shops at sub 1kg in the right sizes. I saw a 54cm frame, painted come into the shop weighing that it is impressive, I'm sure larger sizes and individual frames differ but it's still pretty incredible. The tubes do have really nice subtle shaping 2/3 of a foil in terms of aero.

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Jordan Oroshiba --- Roadie invading Triathlete space for knowledge access

I think the stiffness can easily affect the handling.

Last thing I have heard is that Dimond was trying to quantify the differences in rolling resistance between its beam bike and double diamond ones. Let's see what they come up with because, as you point out, anything involving powermeters won't give valid answers.

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They're going to have a hard time doing that since it's dominated by the tires (if running proper pressures) on a "compliant" bike or not.

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http://bikeblather.blogspot.com/

My problem is with how most of these measures of "stiffness" are performed, i.e. with unrealistic boundary conditions and loading...the only one that comes close is the Cervelo test.

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http://bikeblather.blogspot.com/

Only that people have tried to measure it with two power meters and haven't.

and that I haven't seen a discontinuity in my own power when switching to more or less stiff bikes with my powertap.

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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

Foil "D" is the Scott Foil profile. Just can't say that for brand reasons so I'm just suggesting this.

AND...this is not a knock in any way on Scott bikes. LOVED both my foils and SUPER MAN CRUSH love for my addict! Great bikes and Scott service in Taiwan is above reproach!

Really? OK, well I agree it's a pretty sucky looking aero shape if that's the case.

Perhaps the tube not being vertical changes things when actually in use.

I agree completely with you Watt Matters.

I sent the video and the claim to Scott, but they never responded.

The research was conducted by a Taiwan-based independent frame design-retail company (outsources manufacturing, but design is legitimately completely unique to them..not a sticker brand) in partnership with Taiwan's National Center for High Performance Computing which gives them access to very precise CFD data that goes well beyond the resolution of most CFD software. That does not make it correct, however. Simon Smart, who worked on the Foil, has an incredible and deserved reputation in aerodynamics.

So....even at the level of data presented in this thread...the chart posted earlier and this CFD video...aero is still a he said she said consumer gamble as I have no ability to verify which claim is correct. So that to me significantly dilutes the importance of buying an aero road bike.

And when it comes to tri bikes...80% of aero is all about fit fit fit...and the bike's aero qualities are gravy...and yes...at the pro level....that could be the deciding factor....but for the rest of us, if I have a great fit, I can still take minutes off my 2:23 HIM bike split through more hard work....it's probably a little more challenging for Kienle to shave off an additional 10 minutes through training alone!

i've always enjoyed your posting but lately you've been on fire.
cheers.

Well I would place a lot more value in independent tunnel or field testing of a whole bike or frame using good protocol over a CFD model of a 2-D cross section of one tube.

Don't present false trichotomies.

One can work on optimising position, equipment choices and fitness at the same time. These are not mutually exclusive.

Sure at various points in an athlete's development journey some areas may result in greater gains than others, but that does not mean they should ignore all legitimate ways of improving performance. The only reason I can see for not doing so is one of resource (time, money) constraint or performance doesn't matter much to you (e.g. you're a participant, not a competitor).

This thread is great. Some of you guys should head on over to timetriallingforum in the UK where most folks have simply accepted this science and are now getting on happily with their lives, trying to be as aero as possible and not worrying too much about weight. It makes for a really interesting contrast with the endless aero vs weight debates on ST. They have even accepted clinchers into their lives.

and those guys are fast as shit despite living in a place where it is too cold to train!

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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

I assume this was Topeak?

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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

Work on your abilities then.

A 2D simulation of that profile is inherently wrong. Think about how the aspect ratio of that shape changes when it is part of a 3d dimension tube at an angle. Same is true of the round shape. A round downtube isn't round as the wind hits it, it is oval.

If you want the ability to verify claims, you have options, here is one:
http://anonymous.coward.free.fr/...cda/indirect-cda.pdf

You can also take a trip and visit EROSports or other TrackAero services: http://ero-sports.com/

Other options would be to trust that a preponderance of independent wind tunnel testing and field testing of entire bikes is more accurate than a flawed 2d CFD simulation of one incorrect slice of an entire bike.

At least use all 3 dimensons!

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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

The research was conducted by Velocite bikes during their uncompleted project to design a bike using genetic algorithms and supercomputers

http://forum.slowtwitch.com/forum/Slowtwitch_Forums_C1/Triathlon_Forum_F1/Velocite_and_Supercomputers_to_develop_most_aero_triathlon_bike_ever!!_P3914706/

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http://cds-0.blogspot.com

Oh god, that thing?
I remember thinking that wasn't going to happen.
It is a neat idea but that scale of that project is really huge.

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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

Definitely helps having someone like Simon Smart from Drag2zero in the UK who has not only designed a lot of the fastest equipment but also has done the position setup for many of the fastest riders.

Bob

Because in real life, it makes a difference. People like to throw highschool physics around and assume a lot of things that downplay weight. That may or may not be your reality. (Hint, you're not a vector and your speed isn't constant)

Sounds like a calibration problem. If properly-calibrated, they will differ by a few %/by a handful of watts due to drivetrain friction. In fact, if you're careful you can detect differences between chainring/cog sizes (e.g., 55 x 11 vs. 60 x 12).

Racing on dual carriageways helps a lot, too.

Hi Chris,

We are pretty familiar with the impacts of mass on acceleration around here. Once again I can point you to tools like analytic cycling, or bestbikesplit, which model acclerations so you can quantify the impact.

Even in crit-like acceleration scenarios aerodynamics tends to vastly outweigh mass, here is one such analysis on wheels by Tom. A:
http://www.slowtwitch.com/...nd_Inertia_2106.html

I can point you to others if you are curious.

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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

Or, the difference between a new chain and an old one...or, a hub with a bad bearing, right? ;-)

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http://bikeblather.blogspot.com/

I picked up on the cassette carrier w/ the bad bearing when field testing revealed an unusually high 'Crr', not by comparing crank- vs. hub-based measurements. But, the magnitude of the effect was large enough that you could have measured it that way as well (assuming you could put the cassette carrier on a PowerTap hub).

If only you were certain your powermeters were both precise and accurate - then you'd know.

I'm man enough to admin when I'm wrong, though I was never really against it. I'm pretty critical of any equipment on my Speed Concept. I still would more than likely go with the EVO because I love the feel and Cannondale's crash replacement is outstanding. If I lose a crit by inch is it the bikes fault? Yeah, I'll have no problem blaming the bike :p

Personally I would like to see more frame testing, with just the raw frame, fork and seatpost and nothing added. Maybe some of those tests are, but for me, bike 'X' is not faster than bike 'Y' when half the equipment is different. I can swap handlebars, wheels, and brakes. Just give me numbers for individual equipment.

Unfortunately the latest frames are designed with equipment and rider interaction in mind, so individual pieces could be misleading.

Like the P5 TT bike tests better with a rider than without, for instance.

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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

Things are not that simple if you want to be methodical enough to study the influence of the frame stiffness on performance.

Tests should be done in a velodrome to remove the influence of the wind. The only way to decouple CdA and Crr is by doing laps at different speeds but the cadence should be constant because the hysteretic energy losses taking place in the tire will be influenced by the number of deflections of the tire per unit time caused by pedalling loads (and to remove the influence of cadence on CdA). If speed is modified while maintaining cadence constant, you need a good model to estimate how drivetrain losses are modified as a function of chainring and sprocket size. A treadmill could be a better option due to all these complications.

Both bikes should have exactly the same wheels, same bearing preload (equal tension on the quick release), same drivetrain, etc.

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http://cds-0.blogspot.com

So it's great for optimising quick release skewer tension.

BTW, Coggan was one of the first to describe testing Crr and CdA using these methods.

I wasn't really talking about wheel weight, although yes that counts. As far as bike weight, how exactly do I type in hundreds of slowing down and speeding up over even a 40k in analytic cycling?

How indeed? Gee, if only there were some way to keep track of all those accelerations and decelerations ....

You don't but you can just simulate one such instance and then multiply that by however many instances to get the total energy or time penalty,

BestBikeSplit will automatically simulate any accelerations due to hills/turns etc which is perfect for TT efforts but doesn't really simulate a crit.

Nobody disputes that less weight is good, the question is whether it is worth it to sacrifice say, 200 grams of mass for .005CdA or not. Or whatever the scenario is.

I can tell you there is almost never a case on flat or rolling terrain where a lighter product wins over a more aero product, even with huge accelerations in the mix (hell, just look at Match Sprinter equipment). Once mountains are in the equation though, of course, lighter can be better.

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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

I am certainly not questioning the value of aero in both frame and fit. What I am pointing out, with no success, is that there are legitimate scientific questions about which design is more aero and whether many bikes marketed as aero are in fact aero at all. Obviously, any who cares about the potential of aero to make them faster wants to ensure they are using the optimum aero design.

The 2d model is just one piece of the much wider, and richer, research data they have come up with. I do not represent the company in any way: I do not even own any of their bikes, so I do not have a stake in their position whatsoever. Moreover, accepted research shows trade-offs inherent to any aero design in terms of how it performs across different wind conditions. Take my bike, the P5-6 as an example. With the wind head on to 5 degrees of yaw, it out performs a Shiv or SpeedConcept. At wider yaw angles, the differences narrow and at some point the aero advantage shifts to the Trek. So which bike is "faster?" It depends on the wind conditions and depends on the rider...the faster one rides, the less impact wind yaw angle will have relative to the bike moving forward through air. So here is a concrete example that shows that even on an objective measure of performance, aero performance of any design can gain in some areas and give in others.

As for my comment about fit, I stand by that. As an age grouper, I have qualified and rode to a good bike split at the Ironman 70.3 World Championships and my bike leg is my strength alongside my swim. With my life schedule and physiology, I have worked very hard to maximize my physical potential within those constraints. Thus, the P5 represents a sound investment to gain a little extra performance....sound reasons for an aero frame as minutes can make a difference between a podium and qualifying slot versus come back and try again. And for elite professionals, Craig Alexander is the poster boy for how much a frame can make a difference at that level. I'm not arguing against any of these advantages of an aero frame! :)

I think the simple point I want to make is a) not all aero is created equal and as consumers we should me more critical of the techno-marketing jargon that passes as "science" and b) people who spend huge money on an aero frames but have not optimized their fit and fitness are spending money on very marginal gains and overlooking potentially massive gains. (Especially on the fit area since a great fit will make you faster and requires no additional training effort, much like buying speed through an aero frame, only the potential gains could be even greater depending on one's original position.) Indeed, other far cheaper ways of buying speed such as more aero wheels, clothing and helmets(aero and suited to the rider's ACTUAL race position) can make a far greater difference than even the most slippery frame. So in the end, I guess what I'm saying is that yes, an aero frame is helpful and makes you faster, but should it be the priority in the hierarchy of things that make you faster? No. It's just another part of a complicated number of variables that matter.

And finally, people who disagree with you are not attacking you...I don't really understand the hostility so evident in many of the replies. It's just the internet...we can all relax and smile knowing we probably share more in common as dedicated triathletes than areas we disagree on!

With a standard forward integration model using the well established mathematical model of the physics of cycling, or something like Robert Chung's virtual elevation modelling.

Since you have a speed reading you know the change in speed, and we can reasonably assume mass doesn't change much from second to second, so for each second you can calculate the change in kinetic energy, which will be 0.5 x mass in kg x (change in speed in metres per second)^2. Power of course is that energy change divided by the duration over which it changes.

Then layer on that the maths for other energy demand factors such as air resistance, rolling resistance, along with changes in gravitational potential energy, and Robert's your father's brother, to coin a paraphrase.

When you do the numbers, you'll quickly realise the power demands for kinetic energy changes during time trial / relatively steady state cycling are very small.

The difference in power demand due to accelerating different masses at the same rate
= 0.5 x (velocity change in metres per second)^2 x (mass difference in kg) / (duration of acceleration in seconds)

e.g. accelerating 1mph in one second (e.g. as if you were going from 20 to 30 mph in 10 seconds), then the power difference of adding 2kg while achieving the same acceleration:
= 0.5 x (1/2.237)^2 x 2 / 1
= 0.2 watts more required to accelerate the 2kg heavier bike.

That fifth of a watt extra is a metabolic bummer. And that's a pretty strong acceleration during a TT, considering most changes in speed are due to variations in gradient and wind, not rider effort.

Let's go a bit more extreme, say 0 to 32mph in 10 seconds. Think track standing start, or a crit with a sharp u-turn.
What's the extra power demand of same acceleration with an extra 2kg on board?
20.5W

So unless your bike leg has lots of sharp U turns and the bike is seriously heavier, I don't think you need be concerned about the impact of accelerating extra mass. The energy demand factors are elsewhere.

I think you need to work on your pacing.

Might be oversimplifying things a bit but we are really talking about approx. 600g here (250-300g real world difference between aero frame and non-aero frame, plus 250g for wheels, and another 50-100g here and there). Carbon is an incredible material and 600g isn't very much at all (less than 1% of rider/bike?).

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Either you're draft legal and it doesn't make much of a difference so you might get a good round road bike for the money. or you're not and you can use an actual tt bike. Most of the drag produced is from your body position, an aero bike with a human is nowhere near a tt bike, it is most similar to a round tube so I wouldn't scrutinize my tube shape too much. especially if I'm drafting most of the time anyway.

I don't think Epic-o was responding specifically to my comments, since I was talking about the expected difference between crank and hub measurements of power due to drivetrain friction, not power losses due to frame stiffness.

In any case, though, it is clear he suffers from some misconceptions. For example, it has been shown a number of times that CdA does not change with cadence. Moreover, the close correlation that exists between Al Morrison's Crr values determined via roller testing (at a constant cadence) and those that I have determined via field testing (always using the same fixed gear set-up to control for drivetrain friction, thus at variable cadence) implies that this effect is also negligible.

Dang! I've always wondered why ocean-going vessels are square...it must be because the physics are completely different when the water isn't perfectly still.

http://www.ncbi.nlm.nih.gov/pubmed/16540850

When you tell someone like RChung, who invented the Chung Method, or Coggan who does stuff like: http://www.wisil.recumbents.com/...20road%20cycling.pdf

that he should be more critical of the science/marketing and then show us a 2d CFD video as evidence of this, it is pretty ridiculous.

That would be like walking into transition and telling Kienle how to train properly.

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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

I had no idea Coggan had worked with Doug Milliken, pretty cool. Ohh back when my all consuming passion was something else.

Dude should swim more!

Drafting doesn't make it no effort and at times you may want to break away/be in a breakaway or chasing the front group, there are many situations in draft-legal racing where you want to be as aero as possible. Aero bikes are also a great thing for non-pro triathletes such as myself who can only afford to have one bike and don't want to compromise their daily riding by only having a TT bike but still want to be more aero when racing. The way you're looking at it is kind of flawed. Don't forget also that most draft-legal races are predominantly flat and aerodynamics are therefore more important than weight.

Or asking Shaun Wallace if he'd ever even ridden a fixed gear.

Damn straight brother. Mark Cavendish has done quite well in draft legal races, and he chooses to ride the Venge with deep section wheels. Now I'm going to go hide before somebody posts a photo of Contador on a Tarmac....

I'm waiting to see if Sagan gets on a Venge.

Nobody else will ever win anything!

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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

Right on.

And for one more notch on the bedpost for aerodynamics, I keep pointing people to this bit of analysis from Flo. It takes the ALPE D'HUEZ bike course to make weight a narrow winner over aero in any triathlon in the world, and even then only by 23 seconds. Even at Savageman the 90/Disc prevails over a pair of wheels over 1.1kg lighter.

Think of all the acceleration!!!! And the climbing!! How is this possible?!!

linky
http://flocycling.blogspot.co.uk/...-aero-vs-weight.html

But if a kg means a lot to you just take a leaf out of one infamous IM CHOO pro athlete and piss out a litre in transition.
[edit: not directed at you jackmott, obviously...! ;-) ]

Tom - For the chart on the left, is that the current model (aero) madone or the older generation?

I'm asking because I'm currently trying to decide between a 7 series madone and the emonda SLR. I'd rather be on an aero bike, but I know the resale of the emonda will be much higher when it is time to sell; and that's kind of a big deal for me. If that chart is indeed the latest madone, then it seems like a no-brainer to go with the emonda.

Cannondale didn't offer an aero bike, correct?

correct

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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

Only if the Venge comes with a "cranial / anal removal" procedure.

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I'm fairly certain that's the previous generation Madone.

I don't recall ever seeing any actual drag comparisons between the newest Madone and the older model...IIRC, Trek just claimed it was ~"25W of free power" requirement comparatively. If that's the case, the newest Madone will be much closer to those lower lines in that chart.

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http://bikeblather.blogspot.com/

Hi Andy. Maybe it wasn't the right reply to quote, sorry for that.

I only know one study that studies the influence of cadence on CdA (http://www.hupi.org/HPeJ/0014/0014.html) and, as you comment, it shows that the influence of cadence is nearly negligible. Nevertheless, this study was performed in the MIT wind tunnel that has some well-known blockage problems for cycling applications so I will take the results with a pinch of salt. If you know more trustable sources that have studied this effect, please share.

On the topic of Crr, you shouldn't have found very good correlation between Al Morrison's smooth roller testing Crr and the one you derive by field testing. Al's data on bumpy rollers (something similar to real world conditions, as the bumps induces similar fluctuations of the normal load to the ones caused by pedalling loads) shows significative difference to the data on smooth ones (http://www.biketechreview.com/...py_Data_BTR_rev1.pdf) so you should get similar differences. The combined effect of minimal wind fluctuations, stiffness of the frame, surface roughness relative to the rollers, etc can make up these differences to make you get similar Crr results.

With this I just want to say that everything should be questioned when facing such a complex study.

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http://cds-0.blogspot.com

sigh

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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

You'll find Trek's claim is with deep section aero wheels and their KVF handlebar, as is our new S5's "faster out of the box" claim.

Comparing the frame alone (all other parts the same), the KVF Madone has about 2 Watts (at 40 km/h) higher drag than our R-series.

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

No worries. I was just trying to avoid any confusion.


Chet Kyle tested this (in the TAMU wind tunnel?) as well, but I'd have to dig around to find the exact reference.


I said that there was a good correlation, not that the numbers were equal. In fact, on the road I do get higher numbers than Al (but lower numbers on rollers, presumably because my aluminum rollers are smoother than his plastic ones):

http://www.trainingandracingwithapowermeter.com/...st-results-part.html

I would be nice if you could elaborate something instead of sighting




Good graph!. It would be interesting to replicate that study using bikes with different structural properties but the same aerodynamic ones (by employing a fairing for example) and compare the Crr values derived from field testing.

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http://cds-0.blogspot.com

By any chance would have frame difference for an Evo vs the R-series?

Not to mention that Al only applied his "bump" wires to one of the 2 rear rollers he used (but Crr is from a contribution of BOTH rollers) and the plastic rollers obviously will have some compliance in them by nature.

Interestingly enough though...when I did field testing, Al's "1000hz" numbers matched my on-road estimated Crr fairly well up until ~116 psi. That was probably just dumb luck though in choice of the road ;-)

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http://bikeblather.blogspot.com/

10W (at 40 km/h)

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Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Thanks.

Drag doesn't disappear just because you're drafting. Given a choice, I'd rather pedal less, pedal less hard, and have more in the tank for when it counts.

Did you mean should?

If not, then Coggan found what he found. Why shouldn't he have found that?

we haven't had a good aero idiot thread in a while. this one entertains.

that said, and knowing what I know about aero, I've considered getting a 2nd screen name and doing what this guy is trying to do in order to get a leg up on my competition and keep new people from discovering the secrets ;)

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I don�t do a lot of fast group rides and I have only done one draft legal race. In the fast group rides I have done I have no problem sticking with the fastest guys on my non-aero road bike until we hit a significant hill. In the draft legal road race I did I stuck with the lead pack until we hit a significant hill 14 miles in. For most of that 14 miles I felt like I had no problem keeping up with the group.

To use your example on http://bikecalculator.com - A three pound weight difference on a 1 mile hill averaging 5% grade is about 6 seconds. At the top of the hill when everyone gets back up to speed that�s about 200 feet. If you are 200 feet behind the pack you are well out of the draft, the advantage of an aero road bike is much less than riding in the pack.

If I do upgrade my road bike I am still undecided on if an aero bike is worth it. If there is no compromise on weight, ride or price than an aero bike is a no brainer.

For a solo effort I will use my tri bike every time and not worry about a few pounds.

First, I would be careful using using a calculator that changes the times based on using clincher and tubulars. Second, notice that riding in the drops saves as much time as 3 lbs up the same climb. Third, the calculator does not figure in the drag savings of the aero bike, as shown drag still matters on this climb. Fourth, the weight difference is closer to 1 lbs, so more like 2 seconds.

The reason that it got harder on the hill was because the pace was pushed on the hill. Even on a lighter bike, going up the hill was going to be harder.

Unlike some I don't always jump to an assumption people are idiots to begin with. In my world they have to earn that. Some earn it faster than others, while some are not idiots, just misinformed or need help to learn. Some of the best questions come from those who are misinformed or don't understand. They often ask the questions others are too afraid to ask.

No, reread my post

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That's where you appear to have things backwards.

If one is looking at the bike properties that actually make one faster, then aero should be the driver and the compromise should be made in the other 3 categories...with weight actually pretty much coming in last (although "ride" is probably tied with it for last since you can change the "ride" of a bike more with tire and pressure choice than with frame properties, short of adding a MTB-style suspension).

In other words, get the most aero bike you can afford. Don't worry about the rest.

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http://bikeblather.blogspot.com/

If you had to "short list" 3 aero bikes under $5000, what would they be?
1. Cervelo S3
2. ?
3. ?
Also, if anyone has any data on the new Ridley Noah SL series with their patented F-split fork F-surface technology, I'd like to see it.

1. S3 Ultegra
2. S2 + really nice wheels
3. Venge Pro Race (you'll have to come up with another $500, but it comes WITH Roval 60 carbon clinchers AND their aero road bar)...or, perhaps the Felt AR3?

The Venge looks like a really good deal, actually...

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http://bikeblather.blogspot.com/

I would say the Giant Propel Advanced Pro looks pretty good for the money. You get a set of 55mm carbon clinchers with the price built in and you can pick your build. Cervelo is a classic and the Venge looks pretty enticing too.

+1. you make no effort to normalise the power at which everyone was riding. Roadies attack on hills to drop people, not riding steady state. in fact even if you're riding normally it's quite common to have power go up when riding uphill.

if you were going for most budget I'd say the Giant propel, Avanti Corsa DR and the Neilpryde alize are worth a look as well

I did. It still doesn't answer the question as to why it shouldn't, when in fact it does.

This is exactly my point, on a group ride/race it is easy to keep up on the flats when riding in a pack with or without the added advantage of an aero bike. On the hills where the pace is pushed the advantage goes to the lighter bike.

There can't be much aero advantage at 10-11 mph, can there?

You ain't doin' the same rides/races I am, that's for sure.

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What races are you doing?

Ever been attacked (or have you ever attacked) at 50 km/h in a crosswind? That aero bike will make a difference. When you're biting your stem in a gutter you'll know just how much power gets pushed on the flats.

Ever been attacked (or have you ever attacked) at 75 km/h on a downhill? That aero bike makes a difference.

And at 20 km/h uphill the aero might make a difference too, but significantly less. However, even if you only save 5 watts, you're now saving 5 watts for 20 minutes.

Indeed, this is what I aspire to. If my lack of knowledge grants idiocy, I'm ok with it!

My point has never been that aero bikes do not offer an advantage. My point has been, HOW CAN ONE DIFFERENTIATE **WHICH** aero bike offers more benefits.

I will give two examples of what I am trying to communicate!

Take helmets for example...ones like the Lazer Wasp. When it debuted, it was the shiz, razzle dazzle CDa numbers and all the rest of it. Clearly faster, so the aero experts all declared...just look at the data. And then this little thing called a rider entered the picture...and he looked left, and he looked right, and sometimes, god forbid, he even looked down as he suffered and ground out his 350W performance. The massive tail and its exquisite laminar flow suddenly had the properties of a 15cm square in the breeze. And all of a sudden those numbers blew away like fairy dust in the reality...and the engineers went back to work re-designing a new generation of aero helmets that are truly aero when riders do what riders do when they wear them. This is progress...CFD-Tunnel-Real world and back. So I'm getting at that aspect of aero as well as aero claims not backed by data and real world data.

The other point I would make is this. According to the report, the S5 is absolutely the fastest bike in the test protocol. I do not dispute that at all. BUT....and I do not know the answer to this....would the S5 really be the fastest? As we know, the previous generation S5 was not very stiff in the front end...would that mean even an elite rider would not be able to ride the frame to its fastest speed on a descent because he also needs the bike to hold a line through a curve? I'm not expert; but I do notice the riders on Garmin-Sharp must think a little like me...they generally do not ride the "fastest" bike...they rode the S3 and the R5. Why? They are just stuck in their old ways or are other factors at work? This is an honest question and I'm not on my soap box here!


Here is the famous report I am referring too. I also take great satisfaction that in the end, they say the Scott Addict SL and Canyon are great overall choices....I merely have an Addict Team Issue as my road bike...but damn do I ever love that thing! :)

And...on a final note...for those my ignorance has insulted, I beg your indulgence and sincerely appreciate everything I am learning throughout this thread. I can ride a bike fast, but I truly have no idea why other than I love to ride and love to suffer. Learning the hows and whys of training and equipment is a huge plus of this community.

And...for all the aero schooling I am getting...I thank you too...as I have ammo for my "stiffness" is king friends who cherish their beloved "stiffest road frame" machine; just so I can give them a ribbing. I don't care what bike anyone rides....I just love to ride...simple instinctive joy...but I'm glad there are the numbers guys who are keep making bikes better and better!

All the best to everyone, and by all means, keep at it in this thread. I have literally made notes on what I'm learning here...it has been enjoyable and I am sorry again if I inadvertently sounded like a jack ass....I try to hide this aspect of my personality to the areas of life where I have true expertise but I occasionally fall short!

Crr on smooth rollers should be quite different to Crr in field testing due to the effect of normal load fluctuations and road roughness

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In a group ride, yes having an aero bike is pointless.

In a race if it is always easy to keep up on the flats you will cat up soon and then it won't be.

When you push the pace on short to medium length hills the speed is often pretty high despite it being a hill, often in the 20s.

There isn't much drag at 11mph no, but there is some. The difference in mass between an aero frame and a light one is also very small, usually 100 to 300 grams. GRAMS guys. grams.

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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

You can field test it and find out. I field tested it with a power meter using the Chung Method against the Boardman AiR on a twisty loop and it was faster.


You might recall Thor rode an S5 to two tour de france stage wins, both wins included a big climb, a huge descent where he had the highest descending speed of the entire pro tour, and a final sprint. Seemes like the bike did not hold him back, despite being a bigger guy where frame stiffness would be more likely to matter. (he also won a cobbled stage on an S3 prior to that!)



I think generally people make a bigger thing of stiffness that it really is, here is a fascinating example of that:

http://www.slowtwitch.com/...perception_4571.html

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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

Don't know if it would be in the top 3, but the new Fuji Transonic deserves consideration.

sigh. no no no no no.

If someone rides 400 watts on the flats or the hill, its going to be tough for you to keep up either way. you made no mention of what power people were putting out on the flat or the hill. if in your group ride people were ambling along at 200 watts and then suddenly went off at 400 watts of course you'd be dropped on the hill and find it harder- in fact it's very common! the aero bike or the light bike is not going to help you with 200 watts either way! get a powermeter and ride in your next group ride. I guarunteee you the power ramps up once you hit any hill.

seems you don't exactly how aero works, so this is a VERY SIMPLIFIED analogy

an aero bike might save you somewhere around 10 watts ( comparing best and worst) at say 40kph. drag squares with speed, so a doubling in speed gives 4 times more drag. at 20kph you would be saving somewhere around 3-4 watts ( comparing best to worst). maybe. aero is always 'on', even if you're drafting. the wats savings are slightly less, but it's there.

so say you have an identical twin riding with you in a race. you're on the light but absolutely un-aero bike. he's on the aero bike. you're both in the same race.
Now let's say the race is 'on' with lots of attacking going on around 40-45kph. you see this at critical points in races- just before a decisive corner, hill, the finish line etc. suppose 20% of race time is spent when the race is 'on' . in a 3 hour race thats about ten minutes your twin is pushing ten watts less than what you need to keep up to the peloton's speed. 10 minutes at 10 watts above your FTP could be enough to cook you, while ten minutes at FTP is pretty much sustainable if you have the fitness.

An aero bike won't automatically make you a winner but it can make those 'hard' moments just abit easier, and saves you energy so that you're fresher at the critical moments.

It IS different (in scale, as one would expect with the additional energy being dissipated)...but it correlates (i.e. behaves similarily across tire models).

Here's what Andy said earlier:


Maybe you should look at that link again.

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BS. The torsional stiffness of the S5 is GREATER THAN the original S3, a frame that was "stiff enough" to win a World Championship AND a TdF Green Jersey.

If the stiffness of the front end of an S5 is "holding you back", you're doing something wrong...seriously :-/



Categorically no. See Jack's Thor example above.



Those other factors can be distilled down to visual perceptions and psychological effects. Again, seriously. There are many reports that indicate this is so...

Besides, pro riders aren't necessarily hired for their logic/critical thinking abilities ;-)

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This is becoming tiring, I think I made my point. You don't know the contribution that each of the differences between testing on the road and on the rollers has on the difference in Crr values. It could be that frame stiffness played a role.

Correlation between tire models doesn't have any importance. Correlation of the shift of Crr values between different bikes is what matters here.

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You got me curious, so I reanalyzed all of my data to see if I could ferret out any difference. Here are the Crr results:

1. Bontrager Aerowing TT F & R

on P2T (n=3): 0.0035 +/- 0.0001
on P3T (n=1): 0.0038

2. Veloflex Record F & R

on P2T (n=1): 0.0032
on P3T (n=5): 0.0035 +/- 0.0004

3. Veloflex Record F, Tufo S3 Pro R

on Javelin Arcole (n=2): 0.0043 +/- 0.0001
on P2T (n=1): 0.0052

So for the 1st two sets of tires, Crr was slightly lower when I tested using the P2T than when I tested using the P3T. For the 3rd set of tires, however, Crr came out higher when testing using the P2T vs. a Javelin Arcole. The samples sizes and differences are small, however, so I'm not sure much can be drawn from this analysis.

Tom,

Are you referencing the latest Gen S3/S2? If so, it's the same mold? Why S2 w/aero wheels and S3 Ult (no mention of aero wheels)?

I'm sure this has been covered but has Cervelo released empirical data around the lastest iteration of the S3/S2 vs say last gen S3/S2?

Because he stated a budget of $5000. S3 has a different fork and UDi2 at that level IIRC. Good point though, 1&2 on that list should probably be swapped on a "bang for the buck" basis.

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How do those results change if you compensate for ambient temps?

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http://bikeblather.blogspot.com/

remember that the fork is not any more aero though, on the S3, at present

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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

Is it safe to assume that any watt savings difference from a road bike vs. an aero road bike would be the same for a 120lb rider vs a 180lb rider both with a 4.0 w/kg FTP ? Or is it exponential math of absolute watts or absolute speed that dictates the watt differences ?

The watts savings is a function of speed.
So on the flats the 180lbs rider might save more watts, as he will likely be a bit faster. On the hills, about the same.

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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

Thor is a great example of a rider who wasn't hired for his thinking ability. In 2010 he said he had never seen drugs in cycling and he was shocked when Armstrong confessed to doping. Really Thor?
http://www.cyclingnews.com/news/hushovd-i-have-never-seen-drugs-in-cycling

You've misunderstood. Of course the Crr on road is higher than on smooth rollers, no one has said otherwise.

However a tire that tests better than another on the rollers will also test better on the road.

e.g.
Roller testing shows tire A > tire B by X%
Road field testing also shows tire A > tire B by X%

IOW one can translate the relative performance of roller testing to real world usage.

Hi Tom,

I'm not so sure I agree. The Tour article I referred to explicitly calls out the Cervelo on its "relatively low stability." In addition, in the new S5, Cervelo's marketing team goes to great length to point out the increase in stiffness in the new frame. Those two pieces of information does suggest the feedback Cervelo was getting from its pro riders were for greater stiffness, whether that stiffness simply contributed to "feel" or "speed" or both, I am not sure.

The fact that an elite rider can win with a frame is a vindication of the rider, not always the frame. Also, I don't know how technical the descent referenced was...at those speeds I might imagine it was a straight shot...but as a triathlete and father, not a professional GC rider, I do not have the balls to descend at anything like those speeds given the inherent risks! Big respect for the riders who make that look easy!. (which does demonstrate your point...aren't necessarily hired for their critical thinking skiils)!!

In addition, bike performance is all relative. I think we can all agree that an average carbon frame sold in 2014 would blow the doors off the most expensive racing frame built in the 90s in terms of stiffness, aero, and weight. So the fact the S5 is stiffer than the previous S3 is normal, but not indicative that in today's market, the S5 is stiff enough. And given that Cervelo further stiffened the new S5 frame over the version in the Tour test I have referenced, they obviously saw advantages for doing so. In the end, Tour came down to the same two frames I did in my search for a road bike to replace my Foil Team issue that balanced aero and comfort: the R5 and the Addict SL. Would have been super happy on either bike, but I could get the addict for a whole lot less...and that adds comfort and speed to my wallet! :)

Please name me a new version of a bike that isn't touted as being "stiffer"? That is standard marketing talk for every new bike no? So I don't think this proves anything. Maybe you are correct, but pointing out the bolded section above as proof seems weak.

And that opinion is based merely on values from their torsion rig testing, which has a problem with its boundary conditions. It's pretty clear to see that the Tour torsion test doesn't reflect actual usage and loading.



Yeah, it's too bad that due to faulty tests like the Tour rig and false assumptions by riders that Cervelo has to play the "torsional stiffness" marketing games with everyone else :-/

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I probably should have mentioned I am not a top 1%er like most of the posters here seem to be (ambling along at 200 watts?). I don't have a power meter and it's not in the budget anytime soon but I am definitely not sustaining anything near 400 watts - probably more like 200-250.

I do almost exclusively triathlons and my local club time trial. I usually average 22-23mph on a sprint tri and 20-21 at a Half distance on my cervelo P2 and I don't worry that much about weight. At one local sprint tri my bike split was 30th out of 500 with some decent competition.

I do have a pretty good understanding of aerodynamics, I can see the case of a strong crosswind negating much of the advantage of drafting but in most cases, in my experience and from what I have read, the benefit of drafting is huge. Obviously if someone is massively stronger than you they will get away but I have had no problem sticking with riders who are a little stronger than me on the flats on the group rides I have done.

I will have to take the word of more experienced riders that an aero frame helps in group ride/ draft legal races but I am curious how this transfers over to riders of lower ability. If the weight difference is less than a pound I can easily see the balance being tipped for the aero bike assuming other factors where also close. That three pound figure was put out by someone other than me.

As far as descending I am always one of the fastest guys on my tri bike or non aero road bike. I often pick up a few spots on long descents at hilly tris and I have a few KOMs on descents including a segment into Keene at IMLP.

It is difficult to have a good understanding of aerodynamics in cycling if you also don't use power. They are linked because with a powermeter you can actually do quite accurate field testing of equipment and see the difference it makes. This makes it far easier to spot any spurious marketing claims from bike companies. THe argument of aero vs weight has been well modelled and studied. cervelo and flo have published data with that regards- and the advantage is massively in favour of aero.

most of us are 'ambling' along at 200 -250 watts in our rides most of the time. ( protour races average 230-250 watts over 6 hours, and can then put out 1000 watt sprints at the end. if you can do that for 6 hours hey you may have a shot at being a pro) power is linked to how much muscle mass and fitness you have, so 200W for a 50kg woman on a relative scale may be more of an effort than 200W for a 90kg man. Most riders can easily put out 400 watts- its just how long you can stay there.
a
the fact is drag is drag. it doesn't matter if you're a pro or an amateur, you're still riding through the air. you may not be racing along at an average speed of 42 km/h, like the pros do, but every second you spend riding that aero bike is making it more effecient to keep up to that certain speed.

Is the aero bike for everyone? probably not. if you can't get a good fit on it, another bike that gets you lower ( and maybe even less drag!) may be a better idea. but that's unlikely given the amount of options out there. if you can't afford one, then obviously not ( but there are cheaper options out there.) if you don't race, or don't like riding fast in groups, then mechanical simplicity of a standard bike is nice, and there are plenty of nice non-aero bikes out there.

But if you race, at any level, and are buying a bike to do so, and can afford one- then yes. aero all the way.

Imagine sticking with a slightly stronger rider in one of these group rides. Would it be nicer if you could have spent a little less energy doing that?

Imagine a slightly more strong slightly stronger rider, that you couldn't quite keep with. Would it be nicer if you were able to stay with them for the same energy that allowed you to stay with the slightly less strong slightly stronger rider?

That is how an aero frame helps in a group ride. You are still facing a good deal of wind resistance in a draft.

Massively simplified explanation warning -

If your 200W effort riding into the wind on a flat bit of road was 20% overcoming CRR and 80% overcoming drag, for example. Probably not unrealistic. 40W is fighting CRR and 160W is fighting the wind. You come into a draft and find that your effort falls to 160W, which is a massive 20% reduction in effort from sitting in. Your CRR remains the same, so 40W. Your fight against CRR is now 25% of your effort, you are still spending 75% of your effort pushing the wind out of the way. Does an aero frame still help you then?

Thors descent's were not a straight shot no.
And if you don't have the balls to descend fast, all the more reason to be on an aero bike, you won't be exploring the limits of stiffness anyway.

I'll have your S5 for you ready to pick up.

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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

Enter a cat 4/5 bike race and you will experience it.
At some point someone WILL do 400 watts on a flat, and you might need to do 360 watts to hold their wheel or 345 watts if you had an aero road bike.

345 is less, that will be easier, and that is good.

You can't win a bike race without at some point being in the wind, either.

If you don't race bikes, then there is no point in spending money on an aero bike, or a carbon one.

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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

I recently purchased an s5vwd and love it. I can't imagine wanting a stiffer frame. In fact, this frame felt very stiff once I transferred over my parts. Nothing a few pounds of pressure can't fix, but still a noticeable change over my prior frame. My personal experience is that this bike is a fantasticly nimble machine. I have been tossing it around with sprints, hard corners, etc. Most of this perception probably comes from it being a 54 vs my previous 56 frame. I guess my take away is that all these frame differences are smaller than other variables like tire pressure, size and geometry. You can select/dial those in to get the feel/fit you want. I personally don't place as much stock in opinions /tests of stiffness and ride quality (my own included) and prefer to base my decisions on wind tunnel tests and my ability to get low on a bike.

Instead of a bike/bike comparison I would love to see a test of the complete rider/ bike package. Standard high end setup vs someone that pays attention to the details- aero, position, clothing, latex tubes, good crr tires etc. What is the magnitude of all these marginal gains for a normal rider? V

good tires, clothing, frame, and wheels certainly has more positive effect on bike race results that beet juice does.

Hell, just tires alone do =)

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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

People find it hard to believe that $30 of latex = $5000 in frame!

Never underestimate the power of the simple beet:

http://www.sciencedirect.com/...ii/S1089860314002936

(That said, patient populations in whom NOS-mediated NO production is impaired seem to benefit more.)

latex is so great

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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

Agreed on all points but an aero frame is a small part of an equation. A frame accounts for what, 16% of the total aerodynamics of a bike, and if you add the rider it probably goes down to 6%? For me I'd rather have a frame I know that is comfortable and I don't have achy body parts after 2 hours in the drops. When I shopped for bikes I did look at the S3/2, Madones, and a few others and the geometry didn't match my fit. Granted, we are talking 2-3 centimeters but after a few years and $500 in fitters fees it is dialed in. I know that position puts me in the most comfortable and efficient position and I can stay there for hours.

Maybe I'm sacrificing some speed but my positioning (bent elbows, vertical back), skinsuit, shoe covers, being shaved, and deep dish wheels makes me more efficient than 95% of the riders in a race. I'm only a Cat 4 but at that level very few are min / maxing their aero effectiveness.

After seeing the advantages of an aero handlebar, I will more than likely purchase one before race season. I would like to see someone come out with an aero handlebar that has some consideration to riding IAB. Maybe they do already. Try as I may, my elbows just get too slippery to ride that way.

After getting into triathlon poor, and going from a road bike with Open Pros and Gatorskins up to a TT bike with a skinsuit, fast wheels / tires, and every other positive factor I know the advantages, but I also bought a road bike that didn't fit as well which is a huge factor.

If it is actually impossible for you to get in your ideal position on any of the aero bikes on the market, then that is too bad.
That seems unlikely though given they are all offered in different sizes and you can put different stems on them =)

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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

Who was it who counter-pointed Tom Demerly's constant refrain of "it's all about the fit"*, with "bikes are adjustable and people are adaptable"? Was it Tom A.? Kudos to whomever it was.

*Damn you, Meghan Trainor and your catchy tune!

Going back to the point about the Scott foil's airfoil, but that z plane'd geometry is totally wrong, which suggests the initial foil geometry in the model was wrong. Leading edge is way too sharp. That makes a huge difference. Also it is not mentioned (and is unlikely) that they are modeling the "freestream" quality of the air correctly. For a downtube, it ain't gonna be nice and clean...

3D effects will also take a role in addition to surface roughness.

Don't remember.
"It's all about the fit" is a sales tool usually.
Yes the bike must fit your best position.
No it doesn't have to do so with 0 spacers and a 100mm stem

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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

A trivial aside: when replying to a thread in general, I think it helps to delete the name of the person to whose post you're replying (like I did for this post). That way people know that it is a general reply, and not directed at anyone in particular.

Just trying to avoid con-fusion...*

(*Name the popular media I'm channeling now.)

I have been known to write that (with the word highly in front of "adjustable" and "adaptable"), but I think the original source for that was my buddy Jason Osborne :-)

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If you were going to put clip on bars onto either a aero vs light bike, which would be better if you were to only own one bike (do all training, racing and group cycling)

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Why resurrect this month-old thread? Because a few folks were contending that aerodynamics were of little importance in a draft-legal situation. It is nice to add evidence to this kind of discussion where there is some to be seen. See this video on the front page where those Specialized boys are looking at the relative effect of hand position in drafting and non-drafting situations. Very interesting. Frame aerodynamics may not impact on the same scale as position, but if they do matter at all then on the basis of these results they surely will still matter in the draft.

Summary - the % effect on drag going hoods to drops is HIGHER in the draft, whilst the absolute effect may be a bit less (because overall drag is less). Would have liked them to look at a "good" hoods position, ie forearms parallel to the ground.

And you also get to look at Gwen Jorgensen, who is very lovely.

http://www.slowtwitch.com/...the_draft__4742.html

I saw that video and I must say I was a bit disappointed, not with the outcome, but with the hand positions, both in the drafting video and the other video that looks at the hand positions in isolation. I remember hearing or seeing in other discussions that the hands on the hoods, but with elbows at a 90ish degree angle is actually faster than hands in the drops. I think it has to do with the body position, which in this position is about as low as when you're in the drops, except your arms create less drag as they're less stretched out. It is however more secure, and probably more comfortable (but also less aero) than the invisible aero bar position that they did test. Maybe I'm nitpicking here but the 90 degree hood position feels much more like a breakaway position than the drops position, which I'd use for short punchy attacks (or sprints ofc).

The difference between a proper aggressive position on the hoods and being in the drops will be much less if any at all. She might as well be on the tops if she's sitting so upright. In the ITU peloton and for someone like Gwen the hoods are probably the safer choice as well.