To get a feel for the physics of it, try this experiment at home: Hold a bicycle wheel by the axle, and have a friend give it a good spin so that the top of the wheel is going away from you. Keeping a firm grip, turn the wheel sharply to the left, as if it were the front wheel of a motorcycle. What happens? The wheel twists in your arms, with the top of the wheel going to the right, the bottom to the left. If the wheel were attached to a motorcycle, it would force the bike to lean to the right. Experiment with different forces and wheel speeds and you will find the following: The faster the wheel is spinning, the harder it is to turn to the side and the reacting twist of the wheel depends more on how fast you turn it rather than how far.