|Prev: Front Derailleurs||Next: Chain, Cassette and Crankset|
Tools needed for most repair/maintenance work on rear derailleurs:
Most rear derailleurs are indexed, which means that for every click of the shifter, either up or down, the derailleur will shift the chain from one cog to the next.
Occasionally, you may find that the chain does not quite move onto the next cog when you make a single shift, or else it skips a cog in an overshift. In either case, the rear derailleur needs adjusting. You will also need to follow the steps in this sequence whenever you fit a new cable.
To ensure that the rear derailleur works faultlessly, pay particular attention to its jockey pulleys because this is where oil and dirt can accumulate. Degrease and scrub them every time you clean your bike. Whenever you lubricate the jockey pulleys or the rear derailleur pivots, make sure you wipe off any excess oil.
Parts of a rear derailleur:
Adjusting a rear derailleur
1.Shift the chain onto the biggest chainring and smallest cog, then undo the cable-fixing clamp so that the cable hangs free.
2. Use the high adjuster (usually marked “H”) to line up the jockey pulleys with the smallest cog.
3. Shift onto the smallest chainring and largest cog.
4. Shift back to the smallest cog, then shift upward through each gear. If the rear derailleur does not shift all the way onto the next-biggest cog, screw out the barrel adjuster until it does. If the derailleur overshifts and skips a cog, screw in the barrel adjuster until it stops.
5. Prevent the jockey pulleys from making contact with the bigger cogs by screwing in the adjuster that butts onto the rear derailleur hanger on the frame dropout. Remember to make this adjustment if you fit a block or cassette with bigger cogs than usual.
|Top of Page||Prev: Front Derailleurs||Next: Chain, Cassette and Crankset||HOME|