Causes
Most commonly this occurs when a bicycle with a triple chainring (three gears in front) gets shifted accidentally into the smallest cog. Take a look at the gearing on your bike, and if the chain is sitting on the smallest cog in the front and/or the biggest cog on the back, shifting the bike into a different gear may solve your problem.
Be sure to shift the gears while you're pedaling the bike, however slowly. Shifting the bike while stationary can damage your derailleurs!
Check that the chain is still properly seated on both the front chainring and the rear cogs. Certain circumstances can cause the chain to slip off the gears and break the system. If your chain isn't too tangled up, it should be relatively simple to set it back on the gears in the front and rear—just be prepared to get your fingers dirty. See the Chain Connecting Guide for help on reconnecting your chain.
If your chain comes off regularly, there's likely a larger underlying problem at play. Use our Chain Keeps Coming Off page to get your chain secured.
- No estimateModerate