Bicycle Mechanics - How do I find the correct Bottom bracket for new cranks?

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JJXJ
05-07-06, 10:48 PM
Hey all! I have learned quite a bit just searching the last few days. I now know that I need a 68mm for my bike, but how do I find what spindle length I would need for a new set of cranks? I want to go with the Shimano Deore 170mm cranks.

Thanks for your time y'all!

Justin

r-dub
05-07-06, 11:50 PM
as usual, sheldon is a great source of info:
http://www.sheldonbrown.com/bbsize.html

and this took me exactly 15 seconds to find on shimano's site:
http://bike.shimano.com/publish/content/cycle/sac/us/en/technical_service/compatibility_charts/mountain_compatibility.-MainContent-0003-DownloadFile.tmp/mtb%20fc_bb%20chainline.pdf.pdf

You may need to ask more questions (depending on how much you already know) about how to interpret the shimano site, but basically they are giving you the different configurations possible and the resulting chainline, which you will match up with your rear hub info to determine the proper bb.
JJXJ
05-07-06, 11:56 PM
I forgot to add the info about what is on the bike now. I have the Shimano Dual SIS system. The number on the crank arms is FC-C102-TY30. They also have Shimano YJ stamped into the backs of them around the pedal mount areas. The bottom bracket tube is 68mm, and the crank arms are 170mm.

Thanks again!

Justin

JJXJ
05-08-06, 01:56 AM
Hey! Thanks r-dub! I didn't see that you posted while I was posting. Thanks for the links. I don't see my application listed on either site though. I've been on the shimano site a lot lately, and I even emailed them mid-week last week. I just haven't gotten a response from them. So I figured I would come bother y'all...Thanks for any further help you guys can give. I really do appreciate your efforts!