I've recently bought a new frame. I can't install 1 new bottom bracket in it, because the shell is distorted. Another one I can get in there, but needing to use more and more force as the BB's ends approach the edges of the shell. When getting that one further in, I can already feel the increase resistance on the spindle, presumable from the frame's shell causing the cartridge to distort and further bind the spingle against the ball bearings inside.
The manufacturer is implying that this can't be a warranty item. Of course, this means the frame must be replaced, which is very bad for him.
How is a BB objectively determined to be in spec?
I can see the disparity as I screw in the drive side of the BB, easily being able to see the gap difference from side to side.
(later added:
I didn't mention another part of my test.
I installed both BBs with no problems (hand tightened all the way) into 2 other blank, new frames. I've never had a BB install problem in 30+ times. Each side of the cartridge BBs install fine, its that there's an inherent tolerance that the shells assume as they get closer to being fully threaded in and need to start gently touching each other. If the BB shell is out, then you simply can't thread each side in, or you must thread them with a lot of force.
I could get the BBs started by hand into the suspect frame. I really think the shell was either poorly tapped (poor alignment between the opposing sides) or that the shell was tapped and then welded, and was distored during the welding.
Since I have an older frame by the same mfctr, I tried removing its BB soon after. That BB had even worse problems.
I know it's a problem in their assembly or QC; but the mfctr is implying that there is no way that a shell can be out of spec. I disagree, but don't have a way others might quantify this.
)
The manufacturer is implying that this can't be a warranty item. Of course, this means the frame must be replaced, which is very bad for him.
How is a BB objectively determined to be in spec?
I can see the disparity as I screw in the drive side of the BB, easily being able to see the gap difference from side to side.
(later added:
I didn't mention another part of my test.
I installed both BBs with no problems (hand tightened all the way) into 2 other blank, new frames. I've never had a BB install problem in 30+ times. Each side of the cartridge BBs install fine, its that there's an inherent tolerance that the shells assume as they get closer to being fully threaded in and need to start gently touching each other. If the BB shell is out, then you simply can't thread each side in, or you must thread them with a lot of force.
I could get the BBs started by hand into the suspect frame. I really think the shell was either poorly tapped (poor alignment between the opposing sides) or that the shell was tapped and then welded, and was distored during the welding.
Since I have an older frame by the same mfctr, I tried removing its BB soon after. That BB had even worse problems.
I know it's a problem in their assembly or QC; but the mfctr is implying that there is no way that a shell can be out of spec. I disagree, but don't have a way others might quantify this.
)