I thought I'd share this. Good listening if on the trainer or running. It's a good podcast in general.

https://podcasts.google.com/...rkEegQIDRAI&ep=6

The DT data page is just beautifully done! We had a bunch of stuff on this presented in some white papers written in MS Word in the early Zipp days, but no idea where it is now. The challenge back then was that we were gleaning wattage to spin from power required by a motor driving against the tire to spin the wheel in the wind tunnel. It was a challenge to consistently load the tire in a very minimal, yet full contact way, and then no good way to tare out rolling resistance or bearing losses in the motor and some other stuff... We also later did extensive work on this in CFD looking at hidden vs exposed nipples, spoke shapes, etc

The older data I have from first gen 808/1080 and Hed3/Mavic iO show the spoked wheels in the ~4-6watts to spin (18 and 16 CXRays with exposed nipples and numbers also inclusive of tire and bearing/motor losses) with wattage to spin not affected by yaw angle..this makes the DT/Swisside numbers make a lot of sense. The 3 and 5 spoke have higher translational drags in the middle yaw angles 2.5-17.5, somewhat but not entirely offset by requiring only 1-3 watts to spin, having higher wattage to spin at low yaw, dropping as yaw increases. In certain wind conditions you can get negative wattage to spin on both the H3 and the iO and maybe most interestingly, both of those wheels will give you better low-mid yaw translational drag when run backwards with only slightly higher wattage to spin numbers at higher yaw, in net, both were faster backwards in the aggregate

I haven't tested any of the new generation of wider Hed, Mavic or the new Shimano stuff, so can only speculate on those, but I do have data sets on the H3Deep which was an older design H3 with 90mm fairing and interestingly it was not slower in both translation and wattage to spin than the standard H3 at all yaw angles..which is surprising.

We consistently found 0.5-1 watt increases in wattage to spin for composite spoke wheels in narrow forks, which is largely eliminated by wide set fork blades. I always though it cool that you can hear the difference between forks on these wheels, sound=energy!

Our argument when I was at Zipp wasn't that composite spokes wheels were slow, but rather, they tended to only be faster at yaw angles where most people don't want to ride them.. as they tended to be slower in translational and rotational drag at lower yaw potentially becoming faster at higher yaw angles which were highly unlikely for pro athletes and while more likely for amateurs, there were then handling challenges.

Having said all that, we had sponsored riders like Contador go back to these wheels all the time because they loved the way they looked and sounded. I spent a week before the TdF one year trying to get Contador to ride the carbon 303 on the cobbles as well as the 808 Firecrest over the H3 and in both cases we had him doing dozens of runs and we (as somebody said on the thread earlier) Chung'ed the $hit out of it.. only to have him go against the data which he didn't believe because he knew what 'felt' faster. He used to tell me that the H3 'was the sound of speed'..

Very cool to see the Aerocoach data, is this velodrome data?