Animation brought to you in cooperation with the Musée des Arts et Métiers - Paris.
The velocipede (literally "fast foot") uses a chain set with a fixed sprocket on the front wheel: one turn of the pedals is the equivalent of one turn of the driving wheel.
To travel greater distances with each turn of the pedals it is necessary to increase the diameter of the front wheel: the Penny Farthing is an extreme application of this principle.
The bicycle uses a transmission system that involves a chain connecting two sprockets of different sizes, which provides greater distance to be covered with each turn of the pedals.