Here's the sad pic of my Ultimate lever assembly:

They're about 8 months old, and no idea how it's happened, don't think I've hit that brake lever on anything, and there doesn't appear to be any marks on it. I guess the whole world, and especially Avid would maintain it's because I overtightened the bolts. I use a torque wrench however, and don't think that's the case. It managed to survive 8 months, and about 830 miles(use other bike mostly in bad conditions, and look after this one).
Basically what's my way forward? I did ring Merlin today - where they came from - but he never got back to me. I've looked on Avid parts list, and the lever assembly complete is available, but the guy at Merlin, although he couldn't find the part number, said it'd be £100 anyway if available. I think I may be able to drill right through, and put a longer bolt and nut as a temporary measure, but obviously that'd void any slim possibility of a claim. The guy at Merlin wanted me to send it in, but I can't really see much point, as the problem won't be any different when it's there, and he knows what it is.
Damn - just I've I've bought larger rotors and adaptor brackets.

