Tuning the Gears: Rear Derailleur


Click, click, click, click, clunk! Isn’t it annoying when your gears don’t work? Here’s a quick guide to tuning your gears:

The Rear Derallieur

  • Controls the gears at the back of the bike by shifting the chain onto different sprockets
  • A tighter cable shifts the derallieur to the left, into the bigger sprockets while a looser cable shifts it to the right, into the smaller sprockets

So if the gears aren’t going to the left properly/too slowly, you need to tighten the cable and if the gears aren’t going to the right properly/too slowly, you need to loosen the cable.

How to Tighten/Loosen the Cable

Tools: Fingers01

There is a screw where the cable meets the derallieur which adjusts the cable’s tension specifically designed to fine tune the gears. As you turn the screw anticlockwise, it slowly comes out like a normal screw, pulling the cable tighter on the derallieur. As you turn it clockwise, it screws in, removing tension and loosening the cable.

  • If the gears are not shifting to the left properly, turn the screw anticlockwise.
  • If the gears are not shifting to the right properly, turn the screw clockwise.


What it I can’t turn the screw anymore?

Tools: Allen key (4 or 5mm) and maybe pliers (to pull the cable)P1020020

Then you will need to adjust the cable. Before adjusting, put the derallieur in the far right position as this will release tension from the cable. Set the screw to the midpoint between as tight as it can go and as loose as it can go as this will allow for best fine tuning after we adjust the cable. Push the derallieur left as this removes any remaining tension and use an allen key (usually 4/5mm) to undo where the cable is screwed into the derallieur. Tighten/loosen the cable as necessary (with pliers if you need them) and then use the allen key to screw the cable into place back against the derallieur. Now fine tune the gears to see if the cable is tight/loose enough and if required, repeat again.


The far left/right gear doesn’t work or the chain falls off the cassette:

Tools: Pozidriv screwdriverP1020024

For this we need to adjust the limit screws. These screws are placed at the back of the derallieur. They limit how far the derallieur can shift to the right/left. For Shimano and Sram the top screw is limits the right movement and the bottom screw limits the left movement. For Campagnolo the left screw controls the left movement and right screw controls the right movement.

  • If the chain is falling off the sprocket you need to turn the appropriate limit screw clockwise
  • If the chain isn’t going into the far gear you will need to turn the appropriate screw anti clockwise.


Now you can fix your gears so that they will work for you in the future!

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