Originally Posted by
shogun08
I guess i should be more detailed but when I installed them originally, I used teflon tape and torqued to same spec you mentioned. This lasted a little over a year until a few days ago. I understand that the cups need to be tightened to not become loose but is it normal for the cups to have a certain amount of play in the bb shell? I estimate there is .5-1mm of play where I can wiggle the cups inside the shell. Only until are they are fully tightened is there not play.
My assumption was that even if the cups are not fully tightened in the shell I shouldn't be able to wiggle them inside the cups. The threads still engage and I can still tighten the cups to spec but I just worry about the amount of play when they are loose in the BB shell. Is this normal?
I did a quick check with a caliper and found the Miche cups measure about 29.5mm where other BB cups average out at 29.8 (this included two adjustable chainline BB; Phil Wood and Raceface ST). What you should keep in mind is the Miche system is not the most secure. Phil Wood uses a similar system but requires a thread locking compound similar to loctite, the Phil Wood compound coming in 3 different strengths; low, medium and high (if the BB comes lose with low, try medium and then high). As I said before, the drive side fixed cup style bottom bracket doesn't have this problem and doesn't require any locking compound. You should keep in mind that if your BB shell was ovalised it would normally fit tighter, not come loose. If one starts with the fact the the Miche cups are .3mm smaller in diameter than other BB cups and the Miche BB cups are rattling around in the shell, wouldn't it make sense to try a BB with larger cups? My diagnosing process always starts with the most obvious or cheapists solution and then moves on the more expensive solutions. The cheapists solution would be to warp the teflon tape thicker than before. Next, Loctite is cheap, so I would would try some Loctite (the surfaces have to be absolutely clean for this to work) and if it doesn't work, try another BB.