So I really don’t care about the answer to this question, because I know how small a contribution the frame has to the overall speed of the bike/rider system (maybe 10%… so a bike frame that is 10% faster than another is only 1% faster as a system.). But I still do kind of care.
The data I have seen on the IA is from Felt: a bit slower than a P5 at low yay, faster at high yaw. But I also think it is a bit exaggerated at high yaw as there was no rider in that 2014 data, and I am pretty sure the rider would hurt much of the sailing effect that the deep frame would generate on the back half of the bike.
What other data is out there? What are some wind tunnel experiences? I think about aerocoach saying that the P5 and Speed concept are just fast frames. where does the IA land? Where does the IA disc land (logic says behind the rim brake version or else FElt marketing would be all over it… but how much slower is it?).
There is this Tour article and this discussion on the article.
Thanks! Google searches never showed that one to me… probably because it is german.
The data summary in the thread was also interesting. I assume the comparison times are in hours/minutes/seconds. The best from the worst is about 2minutes. Or 1.5%!!! And given this data only used legs… one might think that differences with a rider might be even less. So there might be a 0.3-0.5% difference between the fastest and slowest bikes (at zero yaw). And i am unsure what rider speed is at, so at human speeds, the difference could be smaller still. And most importantly, within the realm of measurement error in the real world.