The wheel is a very old invention (3000 BC), but the ancestor of the bike only appears in 1850. The velocipede has neither gears, chain nor pedals. The rider pushes with his feet.
The modern bike appears with the "safety" bicycle in 1890, equipped with the following transmission system:
The diameter difference between the front and rear sprockets plays an important role in the operation of the bicycle. The diameter ratio (also equal to the ratio of the number of teeth) is called the gear ratio. Pedaling pace and the gear ratio directly influence the speed, the energy expended and distance.
Click on the board at the upper left or on the sprocket to change the number of teeth.
Turn the pedals or control the pedaling rate with the button slider.