Originally Posted by jimc101

Shims aren't really used for disc brakes any more, the last I had with any brakes were with a M975 caliper (IS standard), as almost if not all current brakes on the market are post mount (with adaptor for IS mount), and have a lot of freedom available for the movement within the mount before it is tightened up. You don't say what hub you have, but doubt it is out of spec, unless there has been a recall on it, as discs and design have been standardized for the last 15 years, same with the frame unless it's damaged / defective.

You haven't mentioned where the pistons on your calipers are, as often these can push out unevenly, or in the case of mechanical discs, can be pushed out independently or be in a fixed position.

If you are still in need of shims, would look at a hobbyshop carrying RC cars, as they use ultra thin shims, which would work.