Carry a chain tool and SRAM PowerLink, KMC Missing Link or similar replacement link for your chain.. The chain tool will allow you to remove the broken link, and the PowerLink makes repair much faster, because it’s designed to slot into a chain without needing tools. Make sure you get one made for your chain. 9-speed chains are a different width than 10-speed or 11-speed.
See the section on using a chain tool for complete instructions.
If you don’t have a chain tool, you can sacrifice an allen wrench to do the same thing as a chain tool replacement. It’s still worth reading the chain tool section as this will give you the theory you need to use your emergency tool.
Tip: Chains break for several reasons:
- Not maintained – rust, abrasion from dirt and general abuse will wear your chain out quickly.
- Cross-chaining – riding in the lowest chain ring and highest gear or vice versa puts lots of stress on the rivet pins of the chain. This can cause them to pop out.
- Stomping on the pedals – riding in a high gear and “mashing” is inefficient and very hard on your drivetrain.
- Hitting obstacles – running the chain into logs, rocks, etc. will cause kinks which then become breaks.
- Trail pixies – probably the highest proportion of broken chains must be caused by trail pixies, because you never do anything listed above, right?