How to tune a rear derailleur

Tuning derailleurs have always intimidated me. Everytime that I mess with them, I make it worse. So I turned to RL, our resident master wrench, for some advice.

Here’s the basic procedure with illustrations. We used the Ibex Trophy with a Shimano Deore LX derailleur. Your bike maybe different but the same principle applies.

First, make sure that the tension on the cable is adequate. It should feel tight like a guitar string. If it’s there’s too much play, then tighten the cable.

Try shifting again. If you’re still having shifting problems, keep reading.

tuning a derailleur

Second step is to shift the chain on the front middle ring:
tuning a derailleur

Third step is to have the chain on the smallest cog:
tuning a derailleur

and then shift to the next cog up:
tuning a derailleur

Now turn the adjusting barrel all the way to the right:
tuning a derailleur

Start cranking the wheel and turn the adjusting barrel to the left while counting the turns until the chain jumps to the next cog.

tuning a derailleur

Once the chain has jumped to to the next cog, shift all the way down to the smallest cog. Turn the adjusting barrel all the way to the right.

Then turn the adjusting barrel 1/2 the number of turns, counter clock wise, you counted (for example, if it took 4 turns for the chain to jump to the next cog, then you turn it 2 turns).

tuning a derailleur

You should now be able to shift gears without hesitation. If you see that there’s a little hesitation, adjust the barrel slightly, taking half turns counter clock wise until you are satisfied with the shifting.

Hope that helps, we just saved you $20-$30!

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