Singlespeed & Fixed Gear - japanese cranks, italian bb

so, i got a bike where the previous rider had put sugino 75s on a campagnolo bottom bracket. i'm thinking about buying a sugino 75 bb, but i've heard some people say that having put the cranks on an italian bb means i have to keep using italian, due to the spindle taper of the bb messing up the cranks. true or false? can i switch to what they're meant to have?

actually, i just noticed a link in another thread to a sheldon brown page that cleared this all up....all sugino is not jis or iso....campy is iso, and njs suginos are iso, meaning nothing's been messed up by this mixing of parts.

just reiterating what's on mr. brown's site, hoping it might help others reading this.

italian BB is the size of the shell, not the taper of the spindle. The BB shell is a little bigger, like 2mm bigger than most other BB shells. I have an italian sized BB (sealed Shimano) on one of my bikes with some old Sugino Super Mighty road cranks, and they work fine. The shimano BB has the same taper as the cranks.

If you are going to get some Sugino 75s, get the right sized BB for whatever bike your using it on. If your going to use those on a track frame, get the Sugino 68 or 75 BB, that will give you the correct chainline.

If your going to use them on a road conversion, you can use a campy BB with the correct spindle length for your application. the tapers are both iso

is there a large chance of splitting sugino 75s if they are mounted on JIS tapered BB?

Shizzy. I got Sugino Mighty Compe cranks and I'm not sure if my spindle taper is JIS. It's a Miche BB, Italian-threaded. Anyone with an educated guess?

italian BB is the size of the shell, not the taper of the spindle. The BB shell is a little bigger, like 2mm bigger than most other BB shells. I have an italian sized BB (sealed Shimano) on one of my bikes with some old Sugino Super Mighty road cranks, and they work fine. The shimano BB has the same taper as the cranks.

If you are going to get some Sugino 75s, get the right sized BB for whatever bike your using it on. If your going to use those on a track frame, get the Sugino 68 or 75 BB, that will give you the correct chainline.

If your going to use them on a road conversion, you can use a campy BB with the correct spindle length for your application. the tapers are both iso


oh, i know the shell, but i'd also been told (wrongly, it turns out) that you can assume difference in spindle sizes based on whether it's italian or japanese. that it's all iso or jis, but naturally it turns out it's not that simple.

Generally speaking, Italian cranks/BBs are ISO and Japanese cranks/BBs are JIS. Such is not the case with 75s, as stated previously (ad nauseum).

Miche BBs are ISO.