[jyl]

Oh, as a practical matter I think the concept is a non starter because (1) there has to be some friction of the weight inside the channel and (2) eventually the battery will run out so nothing will be holding the weight at 3 oclock. Then there will be a 2 kg weight rotating with the wheel. I haven't calculated the centripetal force of a 2 kg weight rotating at radius 35 cm and 300 rpm (40 km/h).

Okay, it is F = M*R*(2*pi/T)^2 where T is the time required for 1 rotation. At 300 rpm, T = 0.2 s. So F = 2*0.35*(2*3.14/0.2)^2 = 690 N. I would think the bike would ride badly, if it were even rideable. With every wheel rotation, he would experience near weightlessness. Not good for traction. At higher speeds, he would be lifted off the ground, or at least his rear wheel would be.