Bicycle Mechanics - Bottom Bracket ?????

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Capecodder
12-04-10, 03:12 AM
Another question on BB's.........

My current BB is a Shimano BB-UN26 with a Shimano XCT crank, and my question is how do I know if it's ISO or JIS, or are these new BB's all ISO?

reptilezs
12-04-10, 04:56 AM
jis is the most common and that is what you have. when buying the bb it will say jis or iso taper but 90 percent or more is jis taper
HillRider
12-04-10, 06:45 AM
Shimano is all JIS. As a general rule most bottom brackets won't say on their packaging what taper they are so you have to know what cranks they are for. Shimano, SR, Sun Tour and most Suguino are JIS. All Campy and some other European makes are ISO.

Capecodder
12-04-10, 06:52 AM
So any Shimano cartridge BB is JIS? I'm just trying to gain some knowledge regarding BB's.......
HillRider
12-04-10, 07:03 AM
So any Shimano cartridge BB is JIS? I'm just trying to gain some knowledge regarding BB's.......
Well, any square taper Shimano cartridge bottom bracket is JIS. The JIS/ISO designations only apply to square tapers and not to later designs like Octalink, ISIS, etc.
Capecodder
12-04-10, 07:11 AM
Well, any square taper Shimano cartridge bottom bracket is JIS. The JIS/ISO designations only apply to square tapers and not to later designs like Octalink, ISIS, etc.

Yes, I was refering to square taper only. Thanks, that is something I did not know. I was under the impression Shimano made both JIS and ISO and that was confusing the heck out of me. Thanks so much for you help.