Bicycle Mechanics - Campy Track BB Taper vs. Sugino 75 taper

I have a track bike with 1983 vintage 165mm campy cranks and BB. I want to replace the crank arms with 170mm cranks and I was thinking of Sugino 75 because they are readily available, use 144 chainrings, and cheap. Plus doing so would allow me to keep the BB in place. Are these compatible? I have read the various threads here on BikeForums and I confess I am simply not able to extract an answer from them although I am sure it is there. So can somebody answer this question?

no.
campy is ISO taper. Suginos are JIS.
you'll need a 109mm symmetrical BB.
a 107 or 110 mm Shimano BB will work as well.

I've heard from various sources that the new sugino 75s are ISO taper.

The Sugino 75 cranks are cheap? News to me.
You can mix-and-match JIS and ISO square-taper cranks and bottom brackets, but it's not a great idea, and it can mess up your chainline since the larger JIS taper crank will slide further onto a smaller ISO-taper bottom bracket spindle than an ISO-tapered crank.

If you want to upgrade to a 170mm crank and are going to get Sugino 75's, just get a new JIS-taper bottom bracket as well. You can get the Sugino 75 bb (109mm symmetrical spindle as baxtefer notes) or a Shimano 107mm square-taper BB. 110mm Shimano bb's aren't symmetrical; the drive-side axle is the same as 107, but the non-drive-side axle sticks out an extra 3mm.

I'm pretty sure the Sugino 75's are JIS taper. JIS is the Japanese standard that was adopted by most of the industry; ISO taper is only used by Campy and a few other European makers (e.g., Stronglight).

huh? where?

A few people I've spoken to have told me that the newer sugino 75s were ISO taper. It doesn't make sense to me, but i'm just throwing it out there. I've got new 75s on a shimano bb in my garage. I should just go measure the gap.

Tim: I didn't realize the shimano 110mm bb were asymetrical. That explains a lot. Why would the non-drive side need to be longer?

Also, where can you find out which of the shimano bbs are symetrical and which are not? I'm assuming the Tange LN79 bb is the same as the UN73, so the 68x110 LN79 is also asymetrical?

@sivat - you may be right about Sugino 75's switching to or being made available in ISO taper. I doubt that's true because I can't think of a reason why Sugino would do this, but it might be true.

So to the OP: this is worth checking on. But even if you can get the 75's in ISO taper, chances are the Campy BB you've got on your bike currently has the wrong size. I'd recommend you sell your Campy BB and crank together on eBay - will likely fetch a pretty penny.

on the asymmetry of Shimano (and Tange?) BB's, I don't know if there's a general database. I started a thread to try to catalog this, and the thread may be useful:
http://www.bikeforums.net/showthread.php?t=196235

Enough with the speculation and "I heard this" and "I think that". Newsflash: there's this thing called the Internet, now. Use it: http://www.suginoltd.co.jp/track_e.html.

Sugino 75 cranks use ISO Taper. The whole point is that Sugino is intentionally emulating a Campy setup.

End of story.

Any reason why they're emulating campy other than that they're doing it?

Enough with the speculation and "I heard this" and "I think that". Newsflash: there's this thing called the Internet, now. Use it: http://www.suginoltd.co.jp/track_e.html.
Sugino 75 cranks use ISO Taper. The whole point is that Sugino is intentionally emulating a Campy setup.
End of story.
Good to know. Thanks. As a business decision by Sugino, this makes sense for only two reasons that I can think of:
1) Campy is associated with high-zoot, potentially snooty componentry standards, and the 75 crankset benefits by association
2) People using the 75 crankset are more likely to buy Sugino's own bottom bracket, since they can't use commonly-available JIS-standard bottom bracket.