How does a “tank slapper” occur? Why wouldn’t a motorcycle simply fall over instead of having the wheel wobble from side to side?

Question

How does a “tank slapper” occur? Why wouldn’t a motorcycle simply fall over instead of having the wheel wobble from side to side?

In: Engineering

Answer 1

Partly because of the rake of the forks. The wheel can rotate left to right, but only around the axis of the front forks.

But, uh that’s all I recall.