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BB question?

urbaindk

The Real Dr. Science
Jul 12, 2004
4,819
0
Sleepy Hollar
I have an old frame that I had converted to SS but the BB went belly up and I need to replace it. The BB was rusted firmly in place and I had to cut it up and beat the living hell out if it to get it out of the frame. I basically destroyed it. My question is how can I determine what size BB to replace it with? I think I can get a measurement off what is left of the spindle but the number I got doesn't jive with any bb's I can find on sale on line.

I have no idea where to start to get a shell measurement. Can I just measure the shell on the frame? I did this and again I don't get a number that makes any sense.

I threaded in the BB from my DH bike so at least I know it has standard threading, nothing weird there.

The frame is 1991 Marin Bear Valley if that helps. Does Sheldon Brown's site have BB sizes? I know it used have seatpost sizes. I'll have to check. Thanks!
 

riderx

Monkey
Aug 14, 2001
704
0
Fredrock
You'll need two sizes:
- the shell size which will be 68 or 73mm (measure the BB shell on the frame)
- the spindle size which will be 110mm, 113mm, etc. (measure the spindle from end to end)