When I first mounted it (Shimano BR-R600, front) 2 months ago it would not tighten down fully. I put a few spacers in front (thanks Sheldon!) so the pivot nut would not prevent the bolt from tightening down and that worked for a while. Now the pivot nut is interfereing with the movement of the outer caliper arm and so when I break it clamps down good and tight, but when I release the break the pivot bolt grinds into the back of the outer arm thus preventing it from recoiling back in to an open position. The odd part is that the nut is still tight and there is no wobble.
After looking at the technical data on the Shimano site I have come to the conclusion that it is indeed not tight enough.
Could (carefully) hack a few mil. off the pivot bolt thus allowing the nut to tighten more.
I already have a 12mm pivot nut--don't think they make em longer than that. Is it possible to buy a longer pivot bolt for this type of brake and perhaps even remake it into a non-recessed R600?
On another subject, I noticed that my break cable (not casing) is kinky in a few places...can I leave it or should I replace it?