A motorcycles is one of the most efficient transportation devices available, especially in the world’s increasingly crowded cities. Although it uses a gasoline engines, it tends to spew out fewer emissions per mile than any automobile. But beginning motorcycle riders have a problem keeping their machines upright when stopped or at very low speeds.
Once the wheels get turning, they act as gyroscopes to keep the motorcycle upright, thanks to a phenomenon known as precession. It’s the force that keeps tops spinning, enables inertial navigation, and makes it possible for 600 pound Harley Davidsons to motor serenely along while on the superslab, unfazed by frost heaves, wind, or the occasional armadillo carcass.