Why is it easier to balance a bicycle in motion than when it's still?

Question

Please explain the theory. The guys feel better when a conversation is technical.

Answer 1

It can be explained with the concept of torque and angular motion. It's the gyroscopic action that makes the rotating body stable. Try to read on gyroscopes. Below is a site explaining the uses about gyroscopes.

http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/bicycle.html

Answer 2

It's called rigidity in space. This has to do with the tendency of a rotating object to remain in one plane of rotation. The turning wheels of the bicycle tend to remain in the upright position and in fact will resist any force that changes their plane of rotation. Of course, you can tilt the bike (that's how you turn it) but as you tilt the wheels the force is actually applied 90 degrees in the direction of rotation. When you stop tilting the wheels tend to remain in that plane, no matter what the angle. Propellers on aircraft display the same tendency. A single-engine plane rotating on take off has a tendency to turn as the propeller tilts upward.