Bicycle Mechanics - bottom bracket tight and not smooth turning
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09-05-11, 10:39 AM
2.3 Trek roadbike all 105 with 300 miles and external bearing bottom bracket. take the chain off and turn by hand and it feels like there's some resistance and you can feel the bearings a little, the bike shop where I bought it says it's better components and they are tighter, nothing to worry about.. spin it by hand, let go and it stops instantly...
is this just characteristic of an external bearing bottom bracket?
thanks in advance.
09-05-11, 10:59 AM
the least they could have done was adjust the preload. takes all of 5-10 mins for some piece of mind. seal drag shouldn't be that tight but depends on many factors. other things to look for, bb chase and face, bb properly tightened
09-05-11, 02:00 PM
My FSA crank was tight and I removed it and reinstalled it to spec for the preload and it is fine now.
There's a difference in the feel of seal drag and normal (correct) preload. It's possible you're feeling the effects of seal drag which goes away as the seals wear and some grease bleeds under them, or it could be excessive preload.
If I had it in my hands I'd venture an opinion, but without actually feeling the drag I can't. Either the shop is right, and it's fine, or the mechanic is too lazy to check/correct what he sees as a minor (not on his bike) problem. One thing you might do is ask him to let you feel another bike with the same or a similar BB, and compare them.
09-06-11, 11:43 AM
thanks all, I need to go back to the shop anyway since the front deraileur still works only occasionally. you've given me a general idea of what to do next.
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