Suntour Superbe road double taper.
 

Hi,

I am wondering if anyone can answer a question for me. I have a late 70s/early 80's suntour superbe crankset for road (double). My question is about the taper. I am familiar with Sheldon Brown's site, which has been very useful, but I'm still not quite sure.
I've tried the crank on a Shimano UN72 BB (which I'm assuming is JIS) and it didn't go on all the way (which is consistent with the crank being ISO). However the Sugino cup and cone BB spindle (which came with the bike and fits the crank well) tapers to the exact same size end as the UN72 and is shorter than the (JIS) UN72, which sounds contrary to what I've read about ISO vs. JIS.
Though they look the same to the naked eye, obviously the crank only goes 2/3 of the way onto a JIS spindle, so I'm assuming its ISO.
I've read also about odd suntour tapers.
But I'd like to be more sure before I order a new BB. Can anyone shed some light on this?
Thanks in advance.

How are you determining it only goes on 2/3 of the way? I realize this might be a really dumb-sounding question, but you didn't say what you've tried.

Coincidental timing. I just picked up a Suntour Superbe Pro crankset as well. Road double. I've also read that some of the cranksets require a unique/odd spindle in the BB.

Is there a way to tell? Or, should I just try it out and see about the fit?

I'd love to use the crankset, but don't want to spend the time/money if I have to track down a Suntour Superbe Pro BB.

According to this links here Suntout cranks use JIS.

http://velobase.com/ViewSingleCompon...m=115&AbsPos=6
http://velobase.com/ViewSingleCompon...m=115&AbsPos=4
http://velobase.com/ViewSingleCompon...m=115&AbsPos=0

I swear I have some Suntour sprint spindles that are ISO.
I think it is pretty easy to tell the difference between ISO and JIS.
JIS just look longer. I might be blowing smoke because I did get the
bottom one wrong from the visual.

ISO
http://velobase.com/ViewSingleCompon...m=119&AbsPos=7
http://velobase.com/ViewSingleCompon...m=119&AbsPos=8

JIS
http://velobase.com/ViewSingleCompon...m=119&AbsPos=4

suntour superbe and superbe pro cranksets (road) have a unique "suntour" taper. I've only ever used these cranksets with suntour bb, so i couldn't tell you if this specific taper is closer to jis or iso. I should measure the differences one of these days. In any case, I've seen them successfully mated to both iso and jis. You just want to avoid swapping back and forth. Oddly enough, my '84 suntour superbe/pro catalog doesn't have any bb info.

Ya, this page lists the Superbe taper
http://equusbicycle.com/bike/suntour...Pro-page-2.jpg

I just bought a Superbe track BB, spindle 70-S. The ends are 12.6 mm broad, measured about 1.5 mm from the end. This is exactly what a Campy Record road spindle from the mid-80s (68-SS) measures. A JIS spindle I have is slightly larger at the same point, 12.7 mm (an even half inch). I think that's what the JIS standard is, while ISO is 12.5, and Campy is in between them, with Superbe, I'm inclined to believe.

So, I think that SunTour's unique taper may be baloney, unless the angle of the taper is different than the standard 2 degrees, which as far as I can tell from measuring, it is not.

Well, the crank only goes about 2 thirds as far onto the UN72 spindle as it goes on the sugino (mw-68)which it fits well with. Both these BBs are listed as JIS. And since yesterday I've found the catalogs online which also list the cranks as JIS. Does that answer the question?

Woops, should have included the quote with that last post- I'm new to this! That was a reply to the very first comment after my original post. Thanks.

(USA zorro)

There are some questions that can only be answered with a precision caliper or micrometer. Why not measure the spindles?

Indeed. I've always wanted a digital caliper, I guess this is as good a reason as any.
Thanks.

I have a Suntour Superbe Pro road crankset on my commuter. I originally had it on a Shimano UN73 and it developed a really annoying creak. I realized it was because (as you discovered) it wasn't seating fully onto the spindle.

Got a Campy Veloce BB and it's been perfect ever since.

Well, I may have found an answer. In Sutherland's, page 3-24, under Non-JIS Bottom Bracket Interchangeability, I found that a Sugino MW-68 spindle is not JIS (like Shimano UN72) but a Campy clone. Like I said before about the SunTour spindle -- it looks like a Campy to me; a spindle with a slightly smaller end; which at 2-degree taper, counts for a lot.

Thanks- that helps to have a category to put the sugino in. I've just taken some measurements and am getting the same results. What's confusing me is that the Phil Wood site says that pre-'93 Campy was JIS and I'm quite sure that this spindle is from the 80's. But I've read some more testimonies to that spindle being Campy ISO so....
Arrhg! I love bikes!
Thank you again, that's really helped.
Cheers!

That it is - the MW-68 is also designed for Campagnolo-pattern thick cups.

http://www.jaysmarine.com/sugino_cam...o_spindles.jpg

MW-68 at top, with an Italian Campag NR spindle below it.

-Kurt

I don't think that Phil Wood says that pre-93 Campy was JIS, just that they recommend a JIS Phil BB for those cranks. They're probably close enough, if you've got a set of cranks that's 15 years old, sockets worn a bit. And the older Campy spindle was in between ISO and JIS.

I think that the year Campy changed to ISO was 1994. But this thread has served one purpose: it appears likely that Sugino Mighty/75, SunTour Superbe and older Campy spindles were essentially the same in terms of the end-of-spindle. That leaves only the distance between bearing surfaces (thin or thick cups, etc.).