Derailleur pulley wheels and jockey wheels.
Derailleur pulley wheels (jockey wheels) guide the chain through the rear derailleur, and worn pulleys cause noisy, imprecise shifting and extra friction. Replacing them is a cheap way to restore smooth shifting. Upgraded pulleys with sealed bearings or ceramic bearings spin more freely and last longer. Check the number of teeth (usually 11, 12 or 13), compatibility with your derailleur and drivetrain speed (9, 10, 11 or 12-speed) before ordering. Narrow-wide pulleys hold the chain better on single-chainring setups. Clean and lubricate pulleys regularly to extend their life. Coloured pulleys add a custom look.
Chains: chains.
Guide wheels keep chains running smoothly.
Related categories: Bicycle Parts, Bicycle Saddle, Bicycle Grips