Curious if anyone has any data (actual from wind tunnel, estimated from pictures, or guesses) of what the drag is for any of the top guys in IM distance racing?
Thanks
No one has an idea. Just looking for a estimate.
Based on what little info we have about power in IM racing, I’d say you have a range of 0.26 (of which there might only be one or two) to well over 0.30 (of which there are plenty).
Thanks.
I just found Sindballe’s power data for Kona and using analytic cycling calculated an estimated CdA of 0.2975
My assumptions were flat windless course
RR = 0.005, sea level, and bike/rider weight of 80kg
Seems that even though Sindballe looks superior aerodynamic his estimated CdA if I did it correctly isn’t that great.
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Just found Faris’ data from the year he won it: same assumptions as above = CdA of 0.275.
where did yo find sindballe’s power for kona?
this would not a very useful piece of info, because even if you only got measurements from riders with great body positions, the total drag would vary vastly based on the athlete’s body size.
that is also why wattage for various pros is also a near useless number for comparison.
the real number that IS useful: sustained wattage per kilo of body weight. now, that is the number where top pro’s will have some very high numbers …
Thanks.
My assumptions were flat windless course
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Here in lies your problem.
i’d be very interested to know the CdA/Kg and Watts/CdA of the top testers in the world. do you know of any list anywhere?
i’d be very interested to know the CdA/Kg and Watts/CdA of the top testers in the world. do you know of any list anywhere?
Watts/CdA is a good (ie, near-perfect) predictor of the relative finishing places in a bike TT or triathlon bike leg. CdA varies with body size, but not nearly so much as it varies with body position. The very best positioned elite TT and pursuit guys will get under 0.21 CdA. Watts/CdA charts only makes sense if you first define the distance over which the watts need to be held.
It’s tough to get a long-course triathlete under 0.25 due to neck and sighting issues and the fact that the bike is somewhat burdened with gear. Plus, nobody rides the whole course at their best CdA. We turn corners, pick up bottles, look around, stand, etc.
Watts/kg is a good relative measure of fitness. But, a high watts/kg fitness level is somewhat wasted if those watts are pushing around a big CdA. Why do you think Armstrong never attempted the hour record? He and his crew were even caught on tape dismissing the idea after a wind tunnel run (in the Armstrong Chronicles series). They knew he ran a higher-than-even chance of failing. Failing is not a good part of the brand management program.
Failing is not a good part of the brand management program.
**That’s worth putting in my quote box. 
**
**How true in so many different places. **
CdA varies with body size, but not nearly so much as it varies with body position.
interesting, but do you have any evidence for this statement?
my experience is that CdA varies widely with body size and position.
and the problem is, you can easily change position, but you can’t easily change body size.
I’m not a top 20 guy (yet!) but I was up far enough at IMFL that packs were not an issue, so these numbers are not influenced by any drafting. And IMFL was flat, and very nearly windless this year.
I had 228w average and around 230w NP if I remember it right, and a 4:43 bike split. I weigh around 150 pounds, maybe a little less, and I could post a pic if that would help.
thanks that would be awesome if you could post a picture? Do you have both side and frontal shots. Thanks in advance.
Well, neither of them are frontal or side shots but they should give some idea. Tires are Michelin pro2 race on a hed3 front, jens bubble-disk rear (808 with cover). Helmet is a taped GA2. I was out of this position for maybe a grand total of 5 minutes throughout the ride.
Thanks
