Many ebikes sport a derailleur hanging out back to giver riders more flexibility than single-speeders. There are exceptions ...

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 ...

For the overwhelming majority of bicycles out there that feature multiple gears, switching between these is done purely mechanically, with a cable. Generally this uses a derailleur, which forms ...