Is my math right? Aero bikes

[justkeepedaling]

I am referring to the links above. I don't see any documentation.

There are in-text citations right in the links...

[mpulsiv]

Why S3? There are plenty of aero frames to choose from.


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[justkeepedaling]

S2 would be even better.

[kgt]

I am referring to the links above. I don't see any documentation.

There are in-text citations right in the links...

Citations like "analyticcycling.com" and "High-Performance Cycling, 2002"?
Ok...

[Krackor]

kgt, do you have some better data about how much aerodynamic drag is experienced while in the draft? The 30% figure is quite common, and a simple google search can find many parties who have corroborated that amount, plus or minus 10%-20% depending on the conditions. If you had any interest in actually learning about this subject it would be very easy for you to do so. Can you demonstrate that your posts are substantiated by some kind of data or evidence?

[justkeepedaling]

^No, no he can't. Because he doesn't believe any data or numbers that relate to aero performance.

How about a couple of papers for you to read, kgt.

http://www.iawe.org/Proceedings/EACWE2013/B.Blocken.pdf

As many real citations as you can tolerate, kgt

http://ir.canterbury.ac.nz/bitstream/ha ... sequence=1

[stormur]

Quote : "The two main limitations of the study are, first, that all cyclists had identical body geometry and position on the bicycle, and second, that only static positions (i.e., no pedalling) were evaluated, without the bicycle(s). The simulations were also performed for cyclists directly behind each other at a separation distance of only 0.01 m."

does it need ANY comment ?

And that's the average value of mostly everything published. REAL data : we will never ever under any condition see it. It's seriously classified by teams and equipment sponsors. That what they give to us are CLAIMS.
So if you believe that anything ( research/ tech data ) from Specialized or Trek or any equipment manufacturer are real data... you should probably train your brain harder than muscles.

Being a bit ( or maybe even a lot ) opportunist, I would rather believe what teams DO instead of what they SAY about any advantages coming from equipment ( including corrections for sponsorship contracts ). That will speak more than any "funny" documents published.
And what they do ? They spend more and more time improving POSITION of rider in wind tunnel/ track in terms of drag vs efficiency. Mostly. In terms of equipment, there's plenty of videos exposing what they use... and I do see some consistency in "winning bikes" All have two wheels ! .

[neomoz]

You'll be very happy on the s3, this is a frame that Garmin cervelo rode on 2 season ago. Got quite a few wins and pros were chosing it over the s5. I ride one and love it, very comfortable for an aero frame, easy to wrench on with components where you normally expect them.

[kgt]

@justkeepedaling

Obviously you cannot understand that these papers confirm my pov. But you cannot understand my pov either so it's loosing time...

[justkeepedaling]

The studies state that approximately 30% drag is saved in drafting. It is comparing CFD to testing in the tunnel WITH BIKES with measured deviations. You think that applies to the rider and not the rider/bike system? There are also studies that show that pedaling is not significantly different than a non-pedaling position with the crank in the right position.

You also did not read the second article whatsoever, which references values directly from field testing and wind tunnel AKA INCLUDING frames and pedaling.

Aerodynamics don't simply go away when you are drafting. The whole system is still requiring power to maintain the gap...

Power and drag are correspond directly. Saving drag on a frame still saves drag in the draft.

On top of that, if you are ever in a breakaway or making a big move, saving drag will always benefit.

AKA Steve Cummings taking noobs to town.

[Franklin]

Just keep pedaling. Some people simply hate facts and science. No use convincing them, they have been taken apart every thread about Aerodynamics.

[kgt]

Or... some people simply love science too much to be persuaded by pseudoscientific data. According to the PhD research mentioned above:

"The gains which could be made from very small modifications to the frame would be minimal compared to those which could be made through changes in position."

"The cyclist contributes significantly more to the overall drag on a cyclist than the frame and wheel combination, and that in order to increase the velocity of a track cyclist the focus should be on improving athlete position rather than the design of the frame or wheels."

"Frame modifications contributed to only 0.3% of the total aerodynamic drag of a cyclist."

"A change to the shape of the bike frame had no significant impact on the drag."

And that was a study on individual pursuit, on a track, where aerodynamics are crucial. Now imagine how negligible is the impact of an aero frame in road racing. That's why I am saying mbrider not to bother that much.

[justkeepedaling]

No one said frame or anything else matters more than position.

Post the link to the paper.

You'd think based on your logic, not a single track cyclist would be using an aero frame. Why is it that all of them are, huh?

In addition, aero frames perform even better at yaw than at zero degrees aoa. So they outperform round bikes even more in the outdoors than they do in the velodrome

[BeeSeeBee]

It was comparing aero frames to aero frames, not aero to standard

Article he cherry picked/misrepresented: http://ir.canterbury.ac.nz/bitstream/ha ... sequence=1

"The gains which could be made from very small modifications to the frame would be minimal compared to those which could be made through changes in position."

"The bike itself accounts for only 30% of the overall drag on a cyclist [Oggiano et al., 2008], so the gains which could be made from very small modifications
to the frame would be minimal compared to those which could be made through changes in position."

This is a statement referencing the limitations placed on bicycle design by the UCI, followed up by referencing the limitations placed on a cyclist's position by the UCI, not some sweeping conclusion about the frames.

"The cyclist contributes significantly more to the overall drag on a cyclist than the frame and wheel combination, and that in order to increase the velocity of a track cyclist the focus should be on improving athlete position rather than the design of the frame or wheels."

Fortunately we have the capacity to do both, much like how "why don't you just take a shit before you ride" is a dumb contrarian answer to someone looking to drop some weight on their bike. The bike contributes significantly less to the overall system weight than it does to the overall system aerodynamics, so why don't you go shit up some threads about that instead?

"Frame modifications contributed to only 0.3% of the total aerodynamic drag of a cyclist."

"A change to the shape of the bike frame had no significant impact on the drag."

*gasp* more cherry picking and misrepresentation from kgt?

"A change in skinsuit had a significantly greater impact on the aerodynamic drag compared to all other changes made to the equipment, and a change to the shape of the bike frame had no significant impact on the drag (<0.3%). This low change in drag for the bike frame is likely to be due to the fact that all bikes used in this study were already optimised in terms of aerodynamics with an aerodynamic frame; a comparison between a non-aerodynamic and aerodynamic frame would likely lead to a greater change in drag."

Care to further explain your position kgt?

[kgt]

No problem at all. I know what I am reading, thanks.

All track/road frames have not the same aero drag obviously. We have seen many tests, actually, where many aero frames (by established manufacturers, designed by aero gurus, tested in wind tunnels etc. etc.) produced more drag than some standard frames. So even if all track frames look like aero we do not really know anything about their actual aero performance. But a whole PhD research on aerodynamics does not even care about comparing the aero performance of different frames. Why? Because according to the research we all know that the impact of the frame alone is negligible. And that in an individual pursuit where the rider is always exposed.
It seems that real science proves you wrong. Sorry...