Basic Gear Indexing
There can be many reasons why your gears may not be shifting as smooth as they used to.
Provided everything is as it should be, you can easily index your gears at home without any fancy tools.
A little knowledge of how the gears work is a good place to start. Without going into too much detail, when you are shifting up into the bigger cogs on your cassette, your cable requires more tension to allow the chain to move up the gears and when shifting into the smaller cogs, the cable needs to slacken to allow the chain to fall back down.
Step 1: Assess whether you need to tighten or slacken
Pop your bike on a repair stand if you have one or flip your bike upside down (be careful to to damage your shifters etc.) and shift through the gears as you use your hand to pedal. If your chain is struggling to shift into bigger cogs, you need to tighten the cable. If your chain is having trouble moving down into the smaller cogs, you need to slacken.
Step 2: Use the barrel adjuster to re-tension
First, locate the barrel adjuster. Your barrel adjuster will probably be on the rear derailleur where the cable meets the derailleur (see picture). For the front derailleur, it’s usually near the shifters.
Turn your barrel adjuster clockwise (outwards) to slacken the cable and anti-clockwise (inwards) to tighten it. Turn the adjuster a quarter turn at a time and check the gear shifting.
It really is as easy as that!
If you are still having problems shifting, it could be down to one of the following:
- Worn chain;
- Worn cassette;
- Misfiring shifter;
- Incompatible parts;
- Cursed by a witch;
- Bent/damaged derailleur, hanger or frame;
- Damaged cable or housing (including dirt and grime causing friction)
Get in touch and we can help diagnose any more serious issues.