0 a type of bicycle gear that works by moving the bicycle chain from one sprocket wheel (= a wheel with a row of tooth-like parts) to another: --
The rechargeable lithium-ion battery pack supplies power to the derailleur motors, which move the derailleurs via worm gears.
His victory was controversial as he was the first rider to complete the race using a modern derailleur.
Hub gears by design are indexed, but for derailleur systems, indexing was an innovation.
The others had derailleur gears for a higher ratio for the sprint.
The derailleur enters production, enabling gears to change without removing the wheel.
Though they are heavier than comparable derailleur systems, internal-gear hub systems generally last longer and require less maintenance.
Unlike some traditional 10-speed gears using a derailleur, there is no slippage when changing gear ratios.
A hub gear system provides greater ease-of-use and safety than a derailleur system, can provide a wide range of ratios, and requires little maintenance.
