Many bicycles have a guard fitted to the chain ring, presumably to keep your trousers from getting oily on the chain, but this it the first I've seen that has a guard on both sides of the chain. Does anyone know what this device is called and where I might buy one?
The bicycle was a Pinnacle Neon if that helps, but it's not the current model. I have already checked on the Evans Cycles web site in case it was described there, but the 2022 model of the Neon does not have this guard.
These can be called chain guards, chainring guards, or bash guards.
Bash guards are meant to protect the chainring from rocks when riding off-road. Chain guards are meant to protect your pant leg, and there's not much point on mounting them on the inside, as far as I can tell.
You'll need to make sure that whatever you get will fit the bolt-circle pattern on your cranks, and it should be sized to the number of teeth on your chainring. You will probably need longer crank bolts (which might be included with the guard), and a special tool for holding the backside chainring nut. If you have multiple chainrings, you can probably mount one to the outside (this will be dependent on the length of the chainring bolts), but I doubt you'd be able to mount one to the inside. It's also possible that the guard will interfere with your crankarm—a lot of them are specific to the model of crank.
Afaik it doesn't matters if they're mounted on the inner or outer faces of the chain ring, they're called chain guards.
The idea with this type is to prevent clothing from getting caught in the mechanism and to provide a simple mechanism to improve chain retention.
For replacement, I'd try my local bike shop, failing that in the UK SJS Cycles carry similiar items e.g. SJS Cycles.
Good luck.
