[MickCooperS]

I need your help!! I have a strange noise, what I can only describe as metal on metal, which randomly happens and sounds like it is coming from front left of my MCS. It started happening when i changed my wheels from s spokes to r90s.... is there some sort of hub ring that I might be missing that should be used with r90s? I heard the noise today (after silence for months) when I was pulling straight up the kerb into my driveway- (the kerb is quite high and I usually move slowly to the edge and then give it revs and climb up onto the driveway)- the noise happened as I revved up to move onto the kerb? Any ideas at all? Cheers for any advice!