Chain coming off on kids bike

[The Family Cyclist]

My youngest has just inherited her sisters ridge back with a whole five gears. However with both her and her sister the chain comes off. Not all the time but much more then I ever get on my bikes. Gears are well set up and change well and the eldest is absolutely fine popping it back on but after inputas to why it might and what can be done

My thoughts are it could be to do with nothing being on the front to keep the chain on at the front. It probably also gets some pretty last minute and slightly ham fisted changes of gear. It only comes off the front.

[LittleWheelsandBig]

Single chainring? Without a front mech, it can be pretty easy for a chain to come off while changing gears. An unsophisticated chainring design and a tension wave in the chain while changing gears (more commonly when changing to a higher gear) often derails the chain, particularly if the chainline is not perfect. Single ring Moultons had this issue at times.

Chainring guards on both sides of the chainring or a chain retention device are the usual solutions.

[The Family Cyclist]

Yeah it's a single chain ring at the front

[LittleWheelsandBig]

There is a chainring guard on the outside of the chainring but the chain falls off to the inside? Something like https://www.ebay.co.uk/itm/153992755267 might be useful.

[The Family Cyclist]

Yeah that's pretty much it. Will get some sort of chain retainer

[Brucey]

you can strap on an old FD as a chain guide and set the limit screws so it doesn't move, if you like.

But before doing that best check for two things;

1) bent teeth on the chainring and
2) that the RD doesn't have slightly stiff pivots, and is still able to keep the chain under tension all the time.

Either of the above could be making things worse than normal.

Also, IME chains with cambered inner side plates tend to stay put slightly better than ones without.

cheers