Originally Posted by
shogun08
Ok thanks a lot everyone for the help. I've really been freaking out about possibly losing the frame but it seems like things could be ok. The bb is english threaded. I took a measure with my calipers on the Inside Diameter of the shell and its roughly 33.85mm at the 6 and 12 position and 34.25mm at the 3 and 9. I'm not sure what the tolerance is for bb shells but this seems a little much. I'm going to bring it to a few shops this week and get some estimates/opinions.
Just because your BB is coming loose is no reason to jump to the conclusion the the BB shell is somehow to blame. Threading aluminum cups into a steel frame, even if it's done wrong will normally do no harm the steel threads. The usual suspect is you; ie user error. Miche BB have a reputation for coming loose if not installed correctly. In order to properly install the Miche BB it is recommend you use clean grease or Teflon tape (some shop mechanics use blue loctite, but the Teflon seems to be the most popular). Prior to anything you need to scrub the BB shell threads to make sure they are clean. The Miche BB has an adjustable chainline, so you need to adjust the drive side cup to the desired location and then tighten the non-drive side to about 25 f/lbs. Next tighten the driveside to about 50 ft/lbs and then do the same on the non-drive side. You must be careful as the cup installation/removal splines are very shallow and strip out easily; especially when your trying to torque in the 50 ft/lbs range. At the very least you should try a conventional BB with a drive side non-movable cup such as Origin8, SKF or Campagnolo Veloce; it would be a shame to pay hundreds of dollars to modify your bikes BB, when all you needed was a new $35 BB..