10-23-2010, 05:26 AM
I just replaced the adjustable bottom bracket on my 1991(?) Bianchi Advantage hybrid. I tried to overhaul the adjustable, but there was a point in the rotation where the axle would get harder to turn and it looked like the axle wasn't coming out of the bottom bracket dead straight. I found lots of little rounded pebbles in the BB when I removed it so I figured the cups had worn unevenly. I bought a new shimano cartridge BB from the bike shop but when I tried to install it the axle would get progressively harder to turn as I tightened the left side lockring. I took it into the shop thinking the BB threads/tube were bent somehow and that the BB needed to be tapped so that the axis was straight. The shop said they did this and installed the new BB but when I got the bike back, the axle still seems hard to turn, certainly harder to turn than when the BB is off the bike. The guys said that is just how new BBs are at first and that it would improve with more riding. Is this true? I didn't expect the tightness of the left side lockring to have any influence on the rotation of the axle. If it is true, will the rotation improve as is or is the lockring too tight? Thank you for any assistance.