Trial-World PM Caliper Mounting Set
Sometimes the PM mountings of frames or forks is not flat. So it is not possible to get the disc free of grinding. It's also possible that a disc has a convex shape, so it's also not possible to get the disc free of grinding, even thought the PM mounting is flat.
With this set of bolts and washers you could tackle the problem.
The washers have a cone, respectively cup shape, so the caliper is slightly inclinable.
The cups (which are bit thicker) have to be placed to the brake caliper mountings, the cones have to beplaced to the frame/fork mounting and bolt head (see pictuire).
The set consists of bolts and washers for one brake caliper.