Many have agreed that bikes are held up at least partly by two powerful gyroscopes – their wheels. A gyroscope is, appropriately, a spinning wheel or a sphere that rotates so fast, it creates forces that make it hard to change its orientation. Scientists, fittingly, use gyroscopes to measure changes in orientation.
As a bike wheel spins, it is rotating around an imaginary horizontal line that goes through its center, creating a force in the direction of its spin. If you try to change the horizontal axis by falling left or right, the spin translates that push into a turning motion.
