So I was following all of the instructions. I mounted the front mech to the braze-on mount. I put the little metal sticker on the frame. Then I was tightening down the support bolt, and I heard a "crack!" I took of the derailleur and looked at the frame. I don't see any cracks or damage. I don't know whether I cracked the frame, separated the frame from the braze-on mount, or it was just a noise and it's nothing to worry about. Any way to be sure?