If you are interested in our other studies from the A2 Wind Tunnel, please be sure to check them out.
Aerodynamic Difference between Sapim CX-Ray and Round Spokes
Does Covering the Valve Cutout on a DISC Wheel Matter?
How Much Drag Does a Clydesdale Build Add to Cycling Wheel?
5. The tire pressures were calibrated with a highly accurate digital gauge.
*UPDATE: If you would like to see the results on an aero graph you can click the links below.
Results in Grams of Drag vs. Yaw
Results in CdA (m^2) vs. Yaw
Good question. Yes, this older work only looked at aerodynamics. As you load a wheel the contact patch changes. The larger issue is the shape of the tire. As you increase pressure the tire gets wider and affects the aerodynamics.
Our newer work combines both aerodynamics and rolling resistance and takes rider weight into consideration. To optimize wheels you have to look at all of them as a system. I hope this helps.
Is this only the aero component? If so what is the related sidewall flex impact of lower tire pressure for say a 200lb rider plus bike? Less pressure, longer contact footprint, more sidewall flex, more heat in tire that came from energy that shows up as rolling resistance…..
Good question. We’ve learned a lot since this article was published. I would recommend looking at our tire pressure recommendation charts for your wheels. We have them on each of our wheel pages.
Great articles. So, If I extrapolate the pressure and tire size from 23 to 28, I come up with 78psi. (It was the same ratio you used in the casing tension diagram).