Hunting is a self-exciting oscillation of a physical system, commonly that of systems incorporating feedback. It also occurs as an uncomfortable phenomenon in railway wheels. A similar phenomenon in automotive tires is known as shimmy. Oscillation is the periodic variation, typically in time, of some measure as seen, for example, in a swinging pendulum. ... Feedback is (generally) information about actions. ... A driving wheel on a steam locomotive. ... Firestone tire A tire (U.S. spelling) or tyre (UK spelling) is a roughly toroidal shaped piece of synthetic rubber which covers the circumference of a wheel. ...

For a full mathematical analysis of the phenomenon, see Hunting oscillation The classical Hunting oscillation is a swaying motion of a railway vehicle caused by the coning action on which the directional stability of an adhesion railway depends. ...