Interesting aero article by Andrew Coggan

Compares a Cervelo PKT (track version of the P2K) against a Javelin Arcole with some thoughts regarding his Hooker frame.

http://www.biketechreview.com/aerodynamics/aero_frame.htm

after an unexpectedly poor performance at nationals due in part to higher-than-expected aerodynamic drag

That’s pretty funny. Other than that, pretty good article.

“While the data suggest (but do not prove) that the Cervelo has less drag than the Javelin”

This strikes me as the same thing as the dietary recommendations from a couple days ago.

…when science and obvious collide.

A non-statistically significant difference = no difference

“Thus, until the opportunity arises to test these two frames head-to-head in a wind tunnel, which one is truly “faster” when ridden by this author remains uncertain.”
.

“I was thinking the same thing. One can never blame the engine.”
By riding with a powermeter, one has the data to know exactly whether or not the engine was to blame.

By riding with a powermeter, one has the data to know exactly whether or not the engine was to blame.

Did AC race at Nationals with a powermeter?

"Did AC race at Nationals with a powermeter? "
That was my understanding though I can’t find a reference off hand.

A non-statistically significant difference = no difference

“Thus, until the opportunity arises to test these two frames head-to-head in a wind tunnel, which one is truly “faster” when ridden by this author remains uncertain.”

Yes, and his testing is fatally flawed: he admits that the Javelin had a front DR mount that he did not saw off. No wonder the Cervelo (track bike with no front DR mount) seemed to be faster. He might as well ahve ridden with a parachute dangling behind him.

"He might as well ahve ridden with a parachute dangling behind him. "

Do you think that a front der mount would make that much difference?

The derailer hanger would not be significant.

The Aero benefits of a frame would be the lowest at yaw angles of 0 degrees. Which is where he was testing, so the differences between the two would be the lowest at this test point. Most of us rarely ride in conditions without a cross wind.

As much as we don’t want to focus on this, the rider has more influence on aerodynamics than the frame.

This study is like trying to determine the different Radar Cross Sectional values of two different stealth fighters while they are both mounted on a big fat steel post.

This is completly inconclusive until he posts picc.
I’ll bet the Cervelo was more color coordinated with his components and clothing, than the Arcole.
Until both bikes are equal fashion wise, the coordinated bike is going to be unquestionibly faster.

It’s not how fast you are, it’s how fast you look

Not sure how much time he has on the track, and it was a 3 min 40 sec race. I would bet he lost more time in the first 333 meters than the last min. Andy rides tough, but those trackies take off like rockets. The bike might make a second or two in that race, he was 7th 11 seconds out or 150-200 meters. G

Thanks for the link!

When I was reading AC’s resume in the bottom I thought it would be funny a paragraph about his posts here, LOL…

Ya saying that wid two identical bikes, and the only diff being one has a front dr hanger (thats bout 2 square cm of flat metal perpendicular to the air flow), that the one wid the front dr hanger ain’t gonna be slower?

“In conclusion, the results of the present experiments suggest that there may be a functionally, albeit not statistically, significant difference in aerodynamic drag between these two frames.”

What an awful “study” coming from the same guy who complains about the scientific validity of the PowerCranks study and those studies of one reported here by users. Where is the statistical analysis? Oh, it might be hard to do with a sample of 1. Where is the double blind? How did he control for placebo effect? What on earth does he mean that there might be a “functional” difference but not a statistical difference. To a scientist, if there is not a statistical difference it should be concluded there is no difference.

I guess this kind of analysis is ok if he does it but it isn’t if any of us does it as none of us are as smart as he is.

Your trying to sell something, Andy wasn’t/isn’t selling anything.

And he doesn’t claim the article to be science. Just because he’s a scientist, it doesn’t mean everything he writes is science.

You never told me if you got the pic I sent you!

I think Dan Empfield summed it up when he said, “You can’t test for this.”

I believe he was talking about aerobars then. I think it applies to a lot of things.

Your trying to sell something, Andy wasn’t/isn’t selling anything.

Andy tries to sell himself.