There are two main reasons for changing your chain. Either it is damaged, or it is worn. It is important to be able to asses how worn a chain is and to do this you can use a chain wear indicator. These are inexpensive and available from your local bike shop.
It is a very useful tool that can tell you if you need to change your chain on the eve of a big cycling event or holiday.
The tool measures the stretch in the chain by slotting into the links. It is recommended that you change your chain around the 0.5% wear mark. Note that if your chain wear is over 0.7% you will probably have to change your cassette too.
All you need is a chain tool, also known as a chain breaker.
How to change the chain – key steps
- Assess the chain for wear.
- Check that the chain isn’t too long.
- Check that the chain isn’t too short.
- Break the chain on a pin that isn’t the joining pin or quick link.
- If the old chain was the correct length, use it as a guide to measure the new chain. Be sure to match up male and female ends. Quick links are much more useful for connecting chains and come standard with SRAM and KMC chains.
- Put the derailleurs in the small front and small rear gears.
- Feed the chain through the derailleurs and jockey wheels. Note the direction of travel if there is one.
- Connect the chain with a quick link. Rotate the chain round so that the quick link is on the top run of chain. By stomping on the pedal you should be able to lock the quick link together.