Join Date: Apr 2009
Location: New Rochelle, NY
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 45 Post(s)
Tagged: 1 Thread(s)
Quoted: 1746 Post(s)
Before doing anything else try this test. Thread in either cup (or half) alone, first the right, then remove it then the left. This will confirm that the threads alone are OK and extend far enough.
Now for the tricky PIA problem, depending n the type of cartridge you have. If the cups are a tight fit on the cartridge, they have no ability to float. Now if the threads on both sides of the BB shell aren't precisely on the same axis - you can sometimes see this when you thread in the cartridge and find that it's off center on the opposite side - both cups are no longer pointing directly at each other and so will tend to bind between the mis-aligned BB threads and the aligned BB cartridge.
There's not much you can do, but I've found 2 tricks that help about 90% of the time depending on the extent of mis-alignment.
1- grease the %$#& out of the insides of the cups and outside of the cartridge where they slip over, and the threads of the BB.
2- install the right side first, but not all the way, and DO NOT TIGHTEN. this allows a bit of float and may be enough for you to get the left side most of the way home. Leave enough room for the right to now be tightened home, then tighten the left. If your BB has a plastic side and metal side, save the metal side for last because it can take more wrench stress.
3- for the worst mis-aligned, try working both sides in together toward the middle, this often works when all else fails by splitting the difference in mis-alignment.
4- if all else fails, look for a cartridge BB system with a bit more float designed in. Or have a good shop retap the shell using taps which are linked via a common central shaft.
An ounce of diagnosis is worth a pound of cure.
“Never argue with an idiot. He will only bring you down to his level and beat you with experience.”, George Carlin
“One accurate measurement is worth a thousand expert opinions”
- Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance