My son has bought rear disc brake set up from Classic and it doesn't come with backing plates. I know they're not a necessity and some people don't use them but as he will be going off road I think it would be better if there were some fitted. The discs are 11" or 28cms across so what would others on here use or recommend?

My thoughts are that it is very difficult to put backing plates in with aftermarket disc brakes, but I could be wrong. You could put a plate on between the rotor face and the inside if the wheel face to stop dirt mud going right through, but not from getting on the rotor from under the car. If the brakes came off a factory fitted rear disc brake car, then maybe you might have a chance.

Kev

I was thinking along the lines of whether there are backing plates that could be adapted to fit.

you could even try getting some backing plates from the wreckers from different models of car that are a closer match then tweaking them to fit.