Why is it that it's much easier to balance on a moving bike than a stationary one? I've heard a few different answers: 1. The wheels of the bike each have their own angular momentum vectors, which like to stay pointed in the same direction, and hence resist tipping from side to side (sort of like a gyroscope). 2. Since the bike is moving, any tipping to one side or the other can easily be corrected by turning the front wheel slightly to one side and getting a mv2/r force that will tend to counteract the tipping. The greater the bike's velocity, the bigger this force is. 3. Something to do with speed making it easier for a rider to orient his/her center of mass in line with the frame of the bike. Not sure how that would work, admittedly. What do you guys think?