Bicycle Mechanics - BB question

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View Full Version : BB question


skiahh
09-30-05, 02:43 PM
I've removed my BB to try and quiet some creaking. Cleaned it all out but before I put it back together, I was wondering just how freely or stiffy the spindle is supposed to turn; I've got a Shimano ES-70. It turns smoothly but is fairly... "firm" I guess. If I spin the spindle and let go it won't continue spinning - it stops immediately. This is my first R&R of a BB, so I'm not sure what they're supposed to feel like fresh out of the box. Thanks.


sydney
09-30-05, 02:47 PM
None of mine keep spinning either.Even fresh out of the box.

antiquebiker
09-30-05, 07:58 PM
Metal deforms under stress and when you are standing on the pedals the bearing is taking the full load. In order for the bearing not to wobble left and right, it needs to feel stiff if it were "unloaded". Commercial motor bearings that are load bearing are "pre-loaded" (tight) for this very reason.


sydney
09-30-05, 08:07 PM
The seals have drag too.