My kid got her first bike recently. It’s a single speed bike but the chain has started to pop off. I tried to loosen the nuts on the rear axle to move it back but that doesn’t seem to help. If anything the chain pops off more quickly now. I’m kind of new to fixing bikes so I apologize if I’m missing something really obvious
by nntp338
5 Comments
Check chain line. Make sure when you tighten the nuts on the wheel you keep the cog in line with the chainring.
Chainring could possibly be bent.
Check your chain for stuff links, or a plate coming off.
You’re probably on the right track suspecting chain tension could be too loose. Sometimes it can be hard to keep the axle pulled back while you’re tightening the nuts. It’ll get easier.
Make sure the bottom bracket is not too loose, if it wobbles it could kick the chain off.
It’s a kids bike, so stuff might be bent, check the front chainring on the cranks, are they flush and straight, no teeth even slightly bent out of alignment… chainguard interference…… siezed chain link….the rear cog might have play init as well, so if you over tension the chain, the next few strokes can either loosen it or over tension it. Neither is great. Just make sure your kid is safe if fiddling with it. No little fingers stuck where they shouldn’t!
You may need to remove the chainguard temporarily to assess and tighten the chain properly. When you have it right, the chain should have only a little bit of slack.