Compared to flats! I also couldn't believe it at first. I'm not sure the theory of it, but I've done long rides with people in both (80+km) and there was no d

Compared to flats! I also couldn't believe it at first. I'm not sure the theory of it, but I've done long rides with people in both (80+km) and there was no difference in speed. I also would do a 16km route as fast as I could, and there was no discernible difference in avg speed or time.