BB replcement help

[Digger]

I need some help finding a replacement bottom bracket. I just removed the old one. It is a Shimano model number BB-UN52. The next line on the sticker says 73. The line after that says BC1.37 X 24. Can someone give me a hand translating those numbers? What do they mean, and how would I go about finding the same or better bottom bracket that would fit? This is for the backup/loaner bike, so I wouldn't mind ordering one and taking a little more time if it saves me any $. If the savings aren't huge, I wouldn't be opposed to picking one up at the LBS either.
If it helps, this is a cartridge, square taper BB.
Thanks.

[Digger]

Nevermind - google helped. 1.37 means the diameter of the cup is 1.37" and the threads are 24 Threads Per Inch. now I just need to measure the axle length in millimeters so the width matches up. That would have been a nice measurement to include on the label.

[patches]

i know, they don't give you the measurement you really need. btw, the 73 refers to the width of the BB shell (the other common size is 68) and 1.37*24 is refered to as "english thread"

i'd stick with shimano for the replacement, it's hard to find a better BB for the price, and your lbs should have at least a few on hand.

[bikeoutback]

I think you need to check out this thread ;)

http://www.morcmtb.org/forums/showthread.php?t=26179

[Ish]

I think you need to check out this thread ;)

http://www.morcmtb.org/forums/showthread.php?t=26179

he needs a 73 not a 68;);)

[Fiveohhh]

he needs a 73 not a 68;);)

nothing a 5mm shim won't fix:D I have one from mine if you need one, otherwise I would think most bike shops would have the shim.

[4Screws]

http://harriscyclery.net/itemdetails.cfm?catalogId=39&id=1203

[Slimpee]

This reminds me that I need a new BB for one of my bikes. I'd replace it but I don't have the lockring tool for the older-style adjustable BB. It's not a hard tool to procure but i'm content to ride it a bit longer. Maybe until it seizes up...

[badandyruh]

nothing a 5mm shim won't fix:D I have one from mine if you need one, otherwise I would think most bike shops would have the shim.

You could in theory do that, but you still need to have the 73mm non-drive cup. You can't use a 68mm non-drive cup in a 73mm shell. I would suggest finding the spindle length(use a calipers), and stay with the 73mm bottom bracket.

[Fiveohhh]

You could in theory do that, but you still need to have the 73mm non-drive cup. You can't use a 68mm non-drive cup in a 73mm shell. I would suggest finding the spindle length(use a calipers), and stay with the 73mm bottom bracket.

I suppose:( Must be my hack thought of fixing things and working in a machine shop. I always seem to want to make everything work:D Having full access to mill, turn or burn parts has its advantages:P

[4Screws]

This reminds me that I need a new BB for one of my bikes. I'd replace it but I don't have the lockring tool for the older-style adjustable BB. It's not a hard tool to procure but i'm content to ride it a bit longer. Maybe until it seizes up...

For one of these...?

http://harriscyclery.net/merchant/370/images/large/bblockring-cr5001.jpg





use the schwinn tools if you don't have access to a lockring wrench.

http://www.ehow.com/images/GlobalPhoto/Articles/2133440/hammerscrewdriver_Full.jpg

[Slimpee]

For one of these...?

http://harriscyclery.net/merchant/370/images/large/bblockring-cr5001.jpg





use the schwinn tools if you don't have access to a lockring wrench.



Yes and I spose I could do it that way if i'm not putting it back in but I might check the spindles/cones and if they're not too worn/pitted perhaps i'll throw new bearings in it and call it good.

On the other hand a new BB isn't terribly expensive and I have a splined cartridge bb tool.

Ahh, F it, let's go bowling.

[Renegade]

with out correct tool for isis lockrings, channel locks in combination w/ soft hammer work just as effectively (protect lockring w/ rag):

http://www.westcoastmall.net/images/0751465.jpg