Can someone please explain to me how to install a tophat sprocket adapter on a GTA-2 frame? Id like to see some pictures also. What is a disc drive offset and how is it measured? The problem I am having is that, to me, it looks like my tophat is too big for the disc to fit inside the caliper, and even if it could fit, it looks like the caliper would touch the sprocket. Can someone please through some advise my way?