[Frank Lee]

Dunno about that. I'm assuming that even under 0 yaw, and ignoring the effects of the spokes and being in the wake of the leading quadrant of the rim and forks, it only needs a small radius for "attached" flow as it were (or weren't). Figure a wheel, wind coming from 3 o'clock... 1:30-4:30 o'clock is where the rim is a trailing edge, 4:30-7:30 is the bottom and hardly moving in relation to still air; 7:30-10:30 is the following quadrant where the rim would be the "leading edge", and 10:30-1:30 is where the rim is speeding along at 2x vehicle speed in relation to the air. I would think that especially on bikes, due to the low speeds, they're almost always in yaw, perhaps severe... so then would rim profile matter?