Is an aero frame beneficial? (light or aero bike faster?)

Discuss light weight issues concerning road bikes & parts.
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BeeSeeBee
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by BeeSeeBee

You're probably thinking of the Chung-on-a-stick, though I believe Zipp has indicated they've used something similar mounted to riders' bikes to get a wind profile for some courses and optimize their rim shapes around those apparent wind angles.

For all of this "may not be applicable in the real world" talk, you guys are aware that field testing is a thing and that it does show correlation with wind tunnel testing right? http://www.cyclingnews.com/features/how-aero-is-aero You can even do it yourself with a power meter!

Nobody is saying that you'll cruise around with a static 30W savings at all times, that would be ridiculous, but there are times where you will have a substantial gain from improved aerodynamics from a frame, wheels, kit, etc. like out on a break away, if you're taking a turn pulling into the wind, etc.

Of course there are tradeoffs, and those have to be weighed for each race, but the bikes absolutely have a place in the quiver of a rider's available tools to help them. And so what if there's only a marginal gain at times? The light 6.8kg bike would make even less of a difference in a flat 200m sprint than something even moderately more aerodynamic. Up a hill, protected in a pack, or where comfort may play a bigger role? don't bring it out then. They may not be the right choice for those of us who can only have one bike (like myself), but if you have easy access to it, why wouldn't you consider it as an option for those days when the race/ride plan will have use for it.

The one thing I do like about slowtwitch is that they're willing to say "show me the data" and consider the conclusions that come from it. Here it's "show me the data; no not that data, it conflicts with my strongly held, but ultimately baseless beliefs."

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Tinea Pedis
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by Tinea Pedis

BeeSeeBee wrote:The one thing I do like about slowtwitch is that they're willing to say "show me the data" and consider the conclusions that come from it. Here it's "show me the data; no not that data, it conflicts with my strongly held, but ultimately baseless beliefs."

:thumbup:

Those in favour come in, for the most part, with tests.

Those against (and you can read back and see it) normally begin their post with "I believe" or "in my opinion"...

by Weenie


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HammerTime2
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by HammerTime2

In God we trust, all others bring data.

thisisatest
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by thisisatest

ras11 wrote:
Again, i.e. just like with deep wheels, a Zipp 1080 might not be the fastest wheel in the pack because of it's shallow stall angle.

im under the impression it worked the other way around: the deeper wheel is faster at greater angles, as the air that comes from the left, passes just in front of the wheel and tries to suck back to the right side of the wheel, has more distance to try to reconnect with the rim before missing the trailing edge. and that at very shallow angles, skin friction, which of course is higher on a 1080 (it has much more skin), plays an overall larger role, reducing its advantage compared to shallower rims.
imo in windy conditions, you ride the deepest wheels you can keep straight (tight group riding would be a slightly different issue of course).
i looked for clear data, ive seen it before but i couldnt find it, besides an old zipp one that compared the 808 to the disc. the disc worked for a much greater yaw range, but since it was a complete disc and not a rim with spokes, i thought it would be too dissimilar to mention.

airwise
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by airwise

BeeSeeBee wrote:
The one thing I do like about slowtwitch is that they're willing to say "show me the data" and consider the conclusions that come from it. Here it's "show me the data; no not that data, it conflicts with my strongly held, but ultimately baseless beliefs."


No I'm saying that data conflicts with the data from Top Velo's wind tunnel tests and from my experience of riding aero WITH a power meter. It exaggerates the gains from what I can see and ignores the losses. That makes it misleading - but highly useful to marketing teams at multinationals.

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BeeSeeBee
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by BeeSeeBee

Link to the top velo test? Or at least a description of their testing protocol? I can find nothing on their site or on the web.

I just posted a link showing a very strong correlation between wind tunnel testing and real world testing and you didn't attempt to even address it (thus making my statement you quoted all the more true). Here it with more analysis.

Conclusion:  
Aerodynamics plays a huge role in cycling efficiency. Our time trial (aero) configuration showed an
aerodynamic savings of 33% over the road configuration, meaning that roughly 70% of the test rider’s
power on the track went into overcoming aerodynamic resistance—a number generally agreed upon by
bicycle scientists.

Based on wind tunnel data and estimated rolling resistance coefficients, Excel simulations of the track
tests predicted total power savings of 25%, compared with 24.1% and 21.7% from the actual track tests.
These numbers tell us that wind tunnel and real world testing can yield fairly comparable results, but
there are still undeniable challenges with real world testing, including environmental variables. 
 

cep111
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by cep111

[quote="BeeSeeBee"]Link to the top velo test? Or at least a description of their testing protocol? I can find nothing on their site or on the web.

I just posted a link showing a very strong correlation between wind tunnel testing and real world testing and you didn't attempt to even address it (thus making my statement you quoted all the more true). Here it with more analysis.

This pdf from Specialized and Steve Hed makes a believer out of me!

tanhalt
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by tanhalt

VNTech wrote:
ras11 wrote:I think you are inferring more of an issue then there is. One or two folks posting about not trusting wind tunnels is not a trend or majority. This is a tangent argument that is sensationalizing the issue of aero road frames. I think most folks believe that aero frames work... it's just clouded in hype (in my opinion).

I agree that wheel aerodynamics and frame aerodynamics should be treated similarly. I involked the same argument in my earlier post, but for a different conclusion. That is, the windtunnel testing for road races should overlay with a higher yaw angle distribution than for TT. Again, i.e. just like with deep wheels, a Zipp 1080 might not be the fastest wheel in the pack because of it's shallow stall angle. Therefore, yes, the wheel analogy is good, but inferring that maximally aero is always better is a bit misleading. I believe that aero frames are not a black and white issue as you may have inferred.

I'm not opposed to promoting this article, I think it'll be good to get feedback from a lot of smart forum members.


I don't think the issue is black and white either. I was merely pointing out the odd disparity between the general agreement that aero wheels are worth running, while aero frames are not. That makes no sense to me. In a race situation, I will take every advantage I can get. That means finding the optimum balance between aerodynamics, handling, and ride quality, since the latter two also can be considered "advantages." I think that with the latest batch of aero road frames, we have reached a tipping point where the drawbacks in ride quality and handling are small enough so as to be easily outweighed by the improved aerodynamics. Before, there was compromise. Now, there really isn't. So why not go aero?

(by the way, my original intention was not to promote the magazine, just to provide a little data for you all.)


Hi Caley...as much fun as it is to talk about the aerodynamic results (these are AERO road bikes, after all) and whether or not the "gains" are truly "realizable", I was hoping we could discuss your stiffness testing results from this test. It seems to me that there's not a very good correlation between the rankings based on your stiffness testing rig protocol and the subjective rankings for comfort, handling and "acceleration". Is it possible you guys aren't quite measuring what you think you're measuring?...and have you thought about possibly changing the test setup? IIRC, you state that the "stiffness" (as measured by the rig) of the 4 frames in the current review were higher than the stiffest one in the last test (the Ridley Noah, I believe) and yet you found the Ridley to be subjectively "too stiff" in actual riding, right?

A couple of things I can think of right away is: Shouldn't the rider weight also be placed on the rig? Does the front fork mount adequately reflect the real boundary condition, or does it unduly constrain at that point...you know, stuff like that?

Have you guys ever considered instrumenting up a road frame with strain gages and gathering "in the field" data on the actual load cases in order to drive a better simulation of those loadings in the testing rigs?

Zigmeister
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by Zigmeister

spartan wrote:roadbike.de did a comparison test of the top 8 new road carbon frames.

evo was rated top bike. it won over sworks sl4, scot foil, giant advanced sl, cervelo r5 vwd, bh ultralight.

http://www.roadbike.de/test/bikes/im-ro ... 5636.9.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;



Can't take these reviews serious when they don't include at least two bikes which have been readily available for awhile now, the Venge and S5. No Canyon Aero, Kuota etc...bikes they are ridden by teams in the Pro Peloton currently. Maybe they just aren't available though for a company to test. But the S5 and Venge certainly are.

But hey, what did I expect, I didn't pay for a magazine or anything.

airwise
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by airwise

The Venge has been reviewed by various publications across Europe with decidedly mixed results.

It's hard not to notice that the top speed merchant at Cervelo rides an R3 and Boonen is happily winning on various non aero frames. Cavendish continues to rack up the results deprived of his Venge and there is to date nothing to suggest that the adoption of an aero frame is of any benefit except in very particular circumstances.

nathanong87
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by nathanong87

i think it's the riders making the frame go fast, rather than the frame making those riders go fast.

tanhalt
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by tanhalt

airwise wrote:It's hard not to notice that the top speed merchant at Cervelo rides an R3...


Huh? It seems to me that Mr. Zabriskie is a BIG fan of the S5.

The bike's insane...these guys are FOOLS not to ride that...fastest bike ever made...


http://www.youtube.com/watch?v=BpHw9hFqx24&feature=player_embedded

NGMN
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by NGMN

airwise wrote:The Venge has been reviewed by various publications across Europe with decidedly mixed results.

It's hard not to notice that the top speed merchant at Cervelo rides an R3 and Boonen is happily winning on various non aero frames. Cavendish continues to rack up the results deprived of his Venge and there is to date nothing to suggest that the adoption of an aero frame is of any benefit except in very particular circumstances.


Boonen was on the new proto roubaix for the classics; it's my understanding that going forward he will return to the Venge.

Anyway, I think the saying "there is to date nothing to suggest... is of any benefit except in very particular circumstances" is ridiculous. There are loads of tests that "suggest" that aero frames are beneficial.

I think more correctly you could say, though aerodynamic testing demonstrates a benefit, people retain doubt about how those benefits play out in the large amount of variables that is bicycle racing. It's less about demonstration of benefit and application to real world; and more about pack cycling races, tactics, etc.

Though, I think you'd have to be a fool to just assume that the 20 watt solo real world tested and wind tunnel demonstrated advantage magically disappears.

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prendrefeu
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by prendrefeu

nathanong87 wrote:i think it's the riders making the frame go fast, rather than the frame making those riders go fast.


Correct.
Exp001 || Other projects in the works.

tanhalt
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by tanhalt

prendrefeu wrote:
nathanong87 wrote:i think it's the riders making the frame go fast, rather than the frame making those riders go fast.


Correct.


Isn't it both? For example, I beat people in races (TTs, crits, whatever...) who I KNOW put out more power than I do. How does that happen? :noidea:

by Weenie


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