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HELP- BB unscrewed on me(7 posts)

HELP- BB unscrewed on mejjparkusa
Jun 16, 2003 6:15 AM
Just had a bike with a chorus italian bb assembled by LBS. On the first ride, the bb unscrewed with about 1/2 inch of thread showing on the drive side before I noticed. LBS doesn't have any idea how it happened. Any thoughts on what was done wrong so it doesn't happen again?
Fixed cup (drive side) use locktite (nm)abicirider
Jun 16, 2003 6:23 AM
re: HELP- BB unscrewed on meM_Currie
Jun 16, 2003 6:28 AM
"LBS doesn't have any idea how it happened..."

Gee, I wonder if they didn't tighten the fixed cup down all the way? It might also have been bearings too tight, although that usually will turn the cup counter to the rotation of the crank, so it ought not to loosen a well-tightened Italian fixed cup. Either way, though, it shouldn't come apart if it was properly assembled.
re: HELP- BB unscrewed on meRusty Coggs
Jun 16, 2003 7:07 AM
LBS is lame if they don't have a clue about a well known issue.Right hand thread of Italian BB is notorious for being self loosening.Fix is tightening 'extra tight', and possibly using teflon plumbers tape.Never needed loctite,and using the wrong kind gets lots of people in trouble.
they didn't torque itterry b
Jun 16, 2003 7:32 AM
If you follow the torque specs for an italian threaded BB, it should not come undone.

Happened to me one time, back when I thought I had a "calibrated" crescent wrench. I've done many since then with a torque wrench set to MFGRs specs, no loctite, no tape and I've never had another one come out.

They know fully well why it came out, they didn't install it properly.
calibrated cresent wrenchRusty Coggs
Jun 16, 2003 8:09 AM
My calibrated metric one works fine.One just needs to know the drill.
calibrated cresent wrenchterry b
Jun 16, 2003 8:20 AM
so does mine - almost all of the time. when it doesn't though it's a real drag. truth be told, I only torque 3 things - BB, crank and stem bolts (and these I do to undertighten.) the rest I agree - once the calibration on your crescent wrench (or forearm for that matter) is set, it lasts forever.