Well I wanted to use my avid brakes but shimano shifter slx not the x7 that came with my bike. These had the avid version of matchmakers which didnt work with the slx.
No 1, the problem, I had a spare hope clamp from when i used the mm clamps on my other bike so i tried the avid and hope together didnt work, it is the avid bolts sit above the clamp but the hope ones are recessed.
No 2, the solution, I filed the hole in the hope clamp to an oval shape and reamed it out a little bit bigger and by using the hope bolts, which have a smaller head than the avid bolts, i ftted the clamp the avid brake and it worked a treat.
I only used hope clamp and NOT a matchmaker clamp as i am to cheap to buy one, but i see no reason why it wont work with the mm clamp the angle seems ok, its just the holes which needed filing into the oval shape.
Disclaimer, i am not a engineer or bike designer or metalurgist so any alterations with void any garauntee and injury could result from the clamp failing, and i am talking out of my hat