Educate me, Alex -- I can understand the shorter toptube because of upper body fatigue from swimming, but why does a triathlon bike need a higher BB and shorter cranks than a road racing bike? Why would one class of riders pedal through corners, whereas the other group coasts through them (as I always do), inside pedal up, weight on the outside pedal? Why would 3- or 4-"spoke" aerodynamic wheels be more suitable for a triathlon than for a road race?