Velocity Ratio
From DT Online
Sometimes, mechanisms are used to translate a small amount of movement into a larger amount (or vice versa).
For example, in a high gear on a bicycle, one revolution of the pedal crank causes several revolutions of the bicycle wheel. Conversely, a car jack requires a lot of movement of the handle to lift the car just a short distance.
This property is known as the Velocity Ratio (VR), and is calculated by dividing the distance moved by the effort by the distance moved by the load.