Just did a service on my rear Avid BB5 Caliper as the damn thing is giving me all kinds of problems. After servicing it I realized it only uses 7-9 mm of engaged thread in the rear caliper mount. I don't have the original bolt for the lower rear disc mount, but I managed to another and use washers to get it to the right size. I find it weird that the bolt is 30mm long but the mount boss only allows me to use 8mm of the thread for it, before it bottoms out. **Edit, does anyone here have Avid BB7s and would you recommend them? (or any calipers under £100) Thanks!