# replace bottom bracket help. Shimano BC1.37 68 zb....what is that?



## computer (Aug 16, 2009)

I think I have most of this figured out. Its a shimano bottom bracket with 1.37 english treading and its shell width is 68mm. What does the zb stand for? What would be a modern replacement? My bottom bracket on my commuter blew out so I need a new one.


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## dru (Sep 4, 2006)

You'll need to give us a lot more info than that if you want help. So far we know you have a 68 mm wide shell using English threading.

What type of crank interface do you presently have?

There's at least three types I can think of that Shimano uses.

Square taper?

Octalink (2 types)?

External bearing?

Of course there's ISIS from the other manufacturers too......


Drew


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## computer (Aug 16, 2009)

I figured it out some of it. The crank is a FC-751 which uses an octalink spline v2. That means I probably should go for a ES71 or ES70, right? I'm a little confused on chainlines. I am running a single speed cannondale with a flip-flop hub in the rear. What version of these BB's do I need and where can I find them?


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## rangeriderdave (Aug 29, 2008)

Your local shop can get whatever you need ,online stores ,ebay.take your choise don't forget you need the right tool to remove and replace it.


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