New aero test: 12 aero frames vs 12 "unaero" light frames

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nd2rc
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by nd2rc

This is marketing ... with a bit of data

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djconnel
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by djconnel

Yes, but the data are important. This was a good test. They went to relative extremes to stack the deck in favor of the light bikes, and still the aero bikes win. That slowtwitch thread is important. In blind tests the difference between the most compliant frames and the least compliant frames was similar to 4 psi difference in tire pressure. On compliance, there's a lot of fuss about very small differences. Same as on weight. If aero differences are relatively small, it's because everything except a well-functioning, clean drivetrain is a relatively small difference. I went from riding a Parlee ESX demo to my old Ritchey Breakaway steel bike and expected to be blown away with how inferior the Ritchey was. But I wasn't. I felt like on most rides I'd be happy on either. Sure, for racing I'd take the Parlee ESX. But I'd take the Ritchey after a tune-up and with good tires after the ESX with a worn drivetrain and cheap tires in a blink. The intrinsic differences are small.

I still want to know what month that lightweight test was done.... but I suppose if I download the Feb version with the aero bike test it will have a reference (too bad I don't speak German, but Google Translate is my friend).

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User Name
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by User Name

Ozrider wrote:The rider is still the biggest "aero" factor, ......
http://tapatalk.imageshack.com/v2/14/09 ... bacbac.jpg
,

I could be wrong, but if that's the same link I saw somewhere else, I think the 17 second time cut for the frame was comparing a TT frame to an "aero" road frame, not an TT frame to a regular one, or an aero frame to a regular one.

In other words, there could be a bigger difference than 17 seconds between a "non-aero", regular frame and something like an S5...der :D
Last edited by User Name on Fri Sep 05, 2014 5:42 am, edited 3 times in total.

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djconnel
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by djconnel

update: all of the data are in Feb 2014, and it only cost me $2.99 on the iPhone app download. Data deluxe, including CdA vs yaw for several bikes, including the Cervelos (delta CdA pretty solid at 0.015 across all yaw angles: very significant). Plus a nice review on iPhone cases.

On the aero test: the S5 and the Merida Reacto came out very close. But the R5 clearly beat the Merida Scultura.

The Storck "aero" frame was actually lighter than the 0.6, which if that means "0.6 kg" is like a 50% error at the tested size.

I agree that for 2000 meters gained in 100 km the test should have been 33.33 km @ 6%, -33.33 km @ -6%, and 33.33 km @ 0, but in the end it won't make much difference. It would be good if I did a mathematical analysis, though (how the drag for a given amount of climbing depends on how that climbing is distributed). Obviously additional descending would increase the emphasis on aero, though, since up-down is faster than just-up: simple energy conservation. I can't quite tell from the German what they did. I'd be surprised if they just did +2% for 100 km.

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RChevalier
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by RChevalier

come on now, it's nothing more than just selective marketing that's all, no different than every other company really. I doubt you will see any company tweeting proudly about a test where their products placed 7th and 11th.

Philbar72
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by Philbar72

Looks to me like marketing flannel. You put me on a friends S5 and I will go faster than him, and he will go slower than me on my TMR01. Reason… because he’s slower and less aero, I’ve ridden both in similar conditions and mine is faster, probably because I’m more used to it! Not much else to it.

The s5 is a horrible bike to ride in any case, if I were to go Cervelo aero, I’d get an S3 and be able to walk again at the end of the ride. The new one looks just as ugly. You may have guessed I’m not a cervelo fan!

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djconnel
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by djconnel

First, I fail to see how it could be marketing for Cervelo -- it's a magazine article, and they get advertising from multiple participants in the test. I'm not even sure Cervelo is among them (I don't recall seeing their ads, but I'm not a regular).

Did you read the SlowTwitch reference?. I hardly think an S5 is "unrideable". Have you even ridden it?

And don't exaggerate claims for aero bikes. A stronger rider will tend to be faster on any bike which fits, which is well maintained, and which doesn't brake. Aero, weight, and stiffness are all marginal.

nd2rc
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by nd2rc

I have an S5, and I find it quite "ride-able" as I ride it quite often. LOL. And now I know I'm fasterer too! :beerchug:

But if didn't live in Iowa, it's quite flat here if you're not familiar with the area, and I lived in Colorado or California I'd buy a "light" bike, regardless of the findings of this test. I still believe horses for courses.

In Cervelo's defense though, if a magazine wrote a test and said my gaskets were the best sealing, I'd sure post/email/mail the heck out of their findings. No need to poo-poo Cervelo for capitalizing on a "third party's" positive findings of their product. Marketing with data.

Imaking20
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by Imaking20

That slowtwitch article is excellent!



Edit: in response to the above comment - I still don't buy that a lighter frame makes a damn bit of difference climbing. For me, as long as the bike is stiff enough - it will climb. My Venge climbs as well as any other bike I've owned... and I live in an area that isn't remotely flat.

I will say that when I had a set of MCCUs on different bikes that I purchased them mostly for "cool" factor. Sure, they felt snappy which made for a lot of fun - but I absolutely didn't expect that I'd notice a difference on longer climbs. Reality proved otherwise. It may very well have just been mental and I'll accept that.

Now, my preference is pretty firmly towards aerodynamics but I think swapping wheels to save 400g+ has more of a felt effect during a ride than a 2 lb lighter build with same wheels.

Zoro
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by Zoro

It may matter to some.
Lately USCycling selects the juniors they will send to Europe heavily weighted on TT performance on a road bike. Last year's winner won by 1.6 seconds at one selection race - on an aero frame. If someone could buy 60 seconds over 4 hours that is a 7 sec placing difference in these junior road bike TTs and could be a nice road trip and team jersey or not.

dunbar42
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by dunbar42

Did you read the SlowTwitch reference?. I hardly think an S5 is "unrideable". Have you even ridden it?


I've read that article but my own experience is that big differences in frame/seat post compliance are detectable. I rode a 2015 Tarmac and 2015 Venge back-to-back recently at a Specialized demo event (20-30 minutes on each bike.) I could feel a very significant difference in ride quality. There was much more sharpness to expansion joints and road imperfections on the Venge. I would lay a $1k bet that I could pick out the difference in a blind test with the condition that the aero seat post couldn't be swapped out on the Venge (that may be scientific but nobody would do that to their aero bike in the real world.) Between my Roubaix SL4 and the new Tarmac I doubt I could feel a difference if the same seat post was installed on both. I have a CG-R seat post on my Roubaix so it would only be fair to control for that when comparing it to the Tarmac.

airwise
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by airwise

Philbar72 wrote:Looks to me like marketing flannel.


It's always been marketing flannel - some people still buy into it. Aero bikes look sexy and 21st century - a marketing man's wet dream.

natiedean24
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by natiedean24

No Felt AR?

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djconnel
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by djconnel

That's a really good point about seat post: the blind test in the Slowtwitch article matched seat post (hard to hide a seatpost).

When I rode the Parlee ESX recently it had a cantilevered seatpost. It seems quite reasonable that had a big impact on how it felt on rough pavement, which was excellent. Indeed that was perhaps the major characteristic of the bike I noticed: how it allowed me to apply power over rough pavement, rather than getting bounced around quite as much. Perhaps I should swap my 0-setback Thomson (somewhat infamous on the vibration transmission factor) on the Ritchey for something similar, other than setback issues.

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by User Name

21.3 Watts less drag for the new S5, compared to the old one (according to Cervelo!!) ? Is that right? Hmmm :D

https://www.youtube.com/watch?v=heMTsjG4qnE

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