Measuring your chain for wear is probably one of the most important things you can do at home to make sure your bike is running nicely! A worn chain can cause shifting issues, or can break more easily.
If you replace your chain at 0.5% wear (for most 10-12 speed chains), you should get around 3 chains to a cassette, and around 6 to chainrings as a very rough guide. If you let the chain wear beyond that 0.5% mark, it starts to cause excessive wear to your cassette and chainrings very quickly, resulting in an expensive repair bill! If you wax your chain (link to waxing article) you can get even more life out of it!
The Park Tool CC-4 is our favourite chain checker, which is recommended by many pro mechanics as it is compatible with any 5-12 speed chain on the market, which many other chain checkers aren’t. It’s cheap, reliable, and simple to use - just check out our video where head mechanic Danny runs through how to use it.