The Derailleur gear system moves the bicycle chain between different gears on both the crank and rear sprocket gearsets. This is achieved by displacing the chain sideways so that it 'jumps' from one ...

Several different types of gearbox are used for bicycles. The three-speed epicyclic-gear hub and the multi-chainwheel Derailleur gears are the most common. The latter can provide a wider range of gear ...