Originally Posted by
elcruxio
At what point does the added aerodynamic drag of a larger wheel and increased hub width become larger than the additional speed gained from a lower angle of attack of a larger wheel?
Theoretically, the threshold is fairly low and within the overall wheel diameter. Realistically the testing so far indicates this is probably not an issue. The total crr of 700c is much lower than the total crr of 26" or 650c for instance, and is becomes even less relevant as the surface becomes rougher and speeds necessarily lower. Triathletes wrung this out fairly well maybe 10-15 years ago.