An
electronic gear-shifting system is a method of changing gears on a
bicycle, which enables riders to shift with electronic
switches instead of using conventional
control levers. The switches are connected by wire or
wirelessly to a
battery pack and to a small
electric motor that drives the
derailleur, switching the
chain from
cog to cog. An electronic system can switch gears faster, and because the system does not use
Bowden cables and can calibrate itself, it may require less maintenance.