A little off topic but it concerns mtb hydraulic disc brakes so I’ve put it in the bike forum.
A friend is involved with Green Power which is a project where school kids engineer a ‘car’ to travel the furthest/fastest running on one battery I think.
Anyway, at the weekend one car overturned and the official enquiry decided that it was due to a small stone getting trapped between the calliper and disc or behind the brake pad that caused the brake to lock on. On inspection the calliper had been ripped off and had made a mess of the disc. The car was travelling at about 25mph at the time of the accident.
My question is this. Is it likely that it was a stone or grit (bear in mind the race was run on a track circuit so not a very stony/gritty area) or is it most likely incorrect alignment or fitting of the calliper and/or brake pad?