The sketch assists students in determining how the pedal and rear wheel gears affect the rotation rate of the rear wheel.[br]The sliders "pedals" and "rear" set the number of teeth on the gears.[br]The sliders "links" represents the number of chain links that have left the gears; increasing values indicate rotation of the pedal and rear wheel.[br]The motion of the rear wheel can best be determined by observing the dark spoke.[br]The lighter spokes will appear to move at a different rate due to a perceptional and sampling phenomenon.