That's an airheart mechanical "floating" caliper. It doesn't bolt to the frame. It slides on to that bracket and thedisc keeps it from flying off. The reason I had to take off my axle was because some genius welded the disc on to it. (Dear god, don't get me to cussing again :Angel_anim
Anyways, I should have clarified in my last post, you
SHOULD be able slide the disc out of the way through an unlocking screw. Don't lose your keystock.