Originally Posted by
cyccommute
The only difference between the BBDB and the BB7 is the rear adjuster. The BB7 added a bolt for a 4mm Allen wrench to make them easier to turn. They use the same pad as a BB7...the one with two hooks on the top...and they are held in place by a spring clip on the top of the caliper. They are adjusted the same as the BB7.
The magnetic pad holder is in the BB5 (I think) and they are generally awful.
No, the early ("type F") BBDB used magnets to hold the pads in place against the piston and whatever the other side dohicky is called. The spring style works fine in the old calipers, in the event the magnets fall out, which they did. I don't know when the type N came out, but it wasn't around too long before they became BB7. The service guide for them, if you can find it (sram doesn't make it available anymore, they seem to want you to buy a new part), explains the other differences as well.