# Great aero wheel comparison



## antihero77 (Jul 26, 2011)

Read this http://www.enve.com/cache/DOC203_WheelTest2.pdf?20120626022821


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## mdmvrockford (Nov 1, 2008)

Interesting that Zipp did not want to participate (as mentioned in beginning of article.


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## skinewmexico (Apr 19, 2010)

What would Zipp have to gain from the test? Not like they'e the #2 wheel in the world.


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## danl1 (Jul 23, 2005)

skinewmexico said:


> What would Zipp have to gain from the test? Not like they'e the #2 wheel in the world.


For one thing, not being seen as a second-rate has-been with something to hide.

More practically, some significant number of people will rely on this as the information they need to make a purchase decision. Even if they wouldn't have come in first, better to be in the race than not to run.

With the same set of information as the testers, I would have done the ranking differently, mostly because I have a different view of the weights they've assigned to the different categories. Anyone with a pre-existing bias will do the same, even if they don't readily realize they are doing it. Zipp took themselves out of the running.

The biggest reason not to is that the wind tunnel numbers that they so happily publish would have not agreed with these, simply because of testing protocol differences. Not worth trying to explain - even legitimate differences would read as marketing excuse, 


Otherwise, interesting reading. As mentioned, I don't necessarily agree 100% with the conclusions reached, but fair enough.

While their watts difference analysis is correct, it would have been a worthwhile paragraph to describe those differences in speed terms, too. For example, at this speed, 20 watts is worth roughly a half mile per hour. Obviously there's a big hunk of 'it depends' in that calculation, but just as another way for people to wrap their heads around the magnitude of the difference.


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## MCubed (Jul 2, 2012)

Nice, thanks for sharing.


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## xjbaylor (Dec 28, 2006)

danl1 said:


> Otherwise, interesting reading. As mentioned, I don't necessarily agree 100% with the conclusions reached, but fair enough.


Just out of curiosity, how would you have ranked the wheels given the information Velo published?


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## QQUIKM3 (Apr 20, 2008)

*What a garbage test. .*

Didn't even have any of Campagnolo's wheels in the test. Weak.


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## Oldteen (Sep 7, 2005)

Interesting they make a point of saying they tested wheels on a complete bike (minus seat in pic?) to create a "real life" environment. Actually the rider is a huge part of that aero environment, particularly re rear wheel at higher yaw angles. IMHO- test would have more credibility if they made at least a few runs with a standardized mannikin rider (as Tour did with their frame testing) to show rider did not (or did?) affect their relative aero conclusions.

Agree it would have been good for authors to include rough analysis of how much the observed differences might (theoretically) mean in actual riding, (e.g. speed at same power for aero, energy cost per some standard acceleration event for inertia). 

Also agree with danl1 that my personal ranking would differ based on same data. IMHO- In aero wheel test, aero (wind tunnel) should be more than 30% of final grade. And braking is FAR more important to me than just 10% weighting.

And I continue to be puzzled at the variances among published test results, even considering differences in testing methodologies. Sure all agree that aero beats old-school 32-spoke box rims and newer "blunt tail" designs are a bit better than older V-shape. But beyond that I'm not sure what to think. One example-
HED's published data shows Stinger 6's drag dropping markedly from 5 to 15deg yaw then rising markedly at 20deg.
http://www.hedcycling.com/aerodynamics.asp
This Velonews test showed a rather different drag pattern for same wheel with a modest decrease in drag from 5 to 10 deg yaw, an increase from 10-15, but then no change in drag between 15 & 20deg. 
And comparing between tests- Tour mag last year found a much larger aero difference between old-style deep V-rim (Mavic Cosmic Carbone) and newer blunt-tail rim designs (Zipp 404, HED Jet), esp above 10deg yaw. This Tour test did not include Stinger, but tested HED 3 showing drag pattern very consistent with HED's web site (pretty flat drag curve across 5-20 deg yaw).

One thing I am sure of is that I enjoy reading/discussing these cycling tech tests.


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## bernithebiker (Sep 26, 2011)

Surely the best thing would be to create some kind of DIN or EN standard. 

That way, everyone tests the same way and we can compare like with like.

If we see big variations between high quality magazine tests, then imagine how easy it is for a manufacturer to skew the results in their favour. Believe nothing that comes directly from a factory.


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## Oldteen (Sep 7, 2005)

bernithebiker said:


> Surely the best thing would be to create some kind of DIN or EN standard.
> 
> That way, everyone tests the same way and we can compare like with like.
> 
> If we see big variations between high quality magazine tests, then imagine how easy it is for a manufacturer to skew the results in their favour. Believe nothing that comes directly from a factory.


Independent standard (like US EPA fuel econ ratings for cars) would be great. But if we had a single standard, what would all those marketing folks do for a living?

Of course I'm skeptical of corporate (marketing) tests, but some can be useful IF supported by independent data. Ballpark speed advantages of aero wheels quoted/calculated from most larger companies stuff (~1-2min for 40k TT vs typical AL road wheel) are fairly consistent with independent tests (Velonews, Tour, Roues artisanales). Measurable, but pretty small in the big picture. I've seen more than a few recreational 17-18mph B/C group riders get sorely disappointed after dumping US$2-3k on high-end aero wheels expecting to immediately hang with 22-23+mph A group.


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## rruff (Feb 28, 2006)

Oldteen said:


> Measurable, but pretty small in the big picture.


On that note I really wish they'd use a better wheel for the "control". How about the ubiquitous Kinlin XR270, CX-Rays, 20f and 24r, with WI hubs? Or better yet the new BHS 472 rim. The only problem would be that aero performance would be close to the other wheels, and people would start to wonder if carbon was really worth it...


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## onthebottom (May 4, 2011)

Bontrager did quite well


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## ergott (Feb 26, 2006)

Oldteen said:


> Independent standard (like US EPA fuel econ ratings for cars) would be great. But if we had a single standard, what would all those marketing folks do for a living?


The problem is that you can get different results even using two different wind tunnels.


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## Oldteen (Sep 7, 2005)

ergott- That's what some auto engineers said years ago about diff dyno's giving diff results. Eventually a single standard (imperfect as it was) was instituted, and eventually refined over the years. And, of course, folks still complain about EPA ratings 

rruff- You make an excellent point. There is huge aero difference between various AL wheels, and best of 'em roughly approach (or even best!) some carbon wheels. Consider Tour's data published in their q4/2011 iPad app, pgs 86 & 96.-
www.tour-quarterly.com
They aero tested a number of all-around wheels (p86) & aero wheels (p96). Traditional 32-spoke handbuilt wheel (WI hubs/OP rims) took 24.1 W @ 40kph (25mph). HOWEVER other AL wheels approximating your suggested build tested much better (~15W), with best AL wheel (Zipp 101) tested @ 14.1W. This was actually better than some mid-height carbon wheels (e.g. 52mm Cosmic Carbone SLR @ 15.4W or 47mm Citec 6000X @ 16.1W ). OTOH the better carbon wheels did offer significant advantage over any AL wheel with Zipp 404 & 808 testing @ 11 & 6.2W, respectively, HED Jet 9 was 9.3W, and the best disc (HED Jet Disc C2) lower yet @ 4.2W.

EDIT- Tour tested in 50kph wind tunnel then converted to values @ 30 & 40kph.


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## rruff (Feb 28, 2006)

Yes! I've seen that test before. Even though it is a carbon rim, check out the Corima... 24mm tall and better aero performance than the Zipp 101. It is just a simple rounded shape, about 23mm wide if I recall correctly.

I've been saying for years that you can get good aero performance from decent aluminum rims with aero spokes.


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## Oldteen (Sep 7, 2005)

rruff said:


> Yes! I've seen that test before. Even though it is a carbon rim, check out the Corima... 24mm tall and better aero performance than the Zipp 101. It is just a simple rounded shape, about 23mm wide if I recall correctly.
> 
> I've been saying for years that you can get good aero performance from decent aluminum rims with aero spokes.



Must admit data on that Corima wheel surprised me. First time I've seen a rim that shallow perform so well in any aero test.


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## danl1 (Jul 23, 2005)

xjbaylor said:


> Just out of curiosity, how would you have ranked the wheels given the information Velo published?


Not saying I'm right, but the value calculation seems weird, and they weight the inertia results a bit more richly than I might.

Based on what I see and understand what's published, the HED's seem to take the top honors overall. 

Again, not saying I'm right - that's what makes a horse race.


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## xjbaylor (Dec 28, 2006)

danl1 said:


> Not saying I'm right, but the value calculation seems weird, and they weight the inertia results a bit more richly than I might.
> 
> Based on what I see and understand what's published, the HED's seem to take the top honors overall.
> 
> Again, not saying I'm right - that's what makes a horse race.


I can see that. I just find it interesting how the rankings change for individual based on the weighting of the criteria. Based on what I would buy with my own money, it would be the Bontrager because I appreciate the versatility, the weight (I ride in the city and sprint from a lot of lights) and the "value." For a TT bike, or something similar, I would have to agree that the HED would finish first in my book. 

If someone offered to just give them to me, however, I would probably take the Enve's. They are just cool.


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