I'm builing up a cross bike, and I'm using Hayes MX2 mech discs. The only problem is that the disk doesn't seem to line up properly. It fits into the slot and all, but the pad that does the pushing is rubbing on the disc, even when released completely. There doesn't seem to be any sort of float adjustment. Would filing down the inside of the frame where it attaches to the brake be an option? Or would there be an easier way? Thanks.