rothenfield1

I bought a Suntour Superbe Pro double crank dating to '85 according to the stamp code. I looked it up on Velobase and found conflicting info on the 2 that appeared similar. One was a single/pista, but the "S" stamped on the arm was the same as mine. It was listed as ISO taper. The other was a double, but was listed as a JIS taper and recommended a 109 spindle length. The seller told me he ran a Superbe BB with 113 length, but a shorter one would probably have provided a better chainline.

This is going on an Italian BB shell with Campy 7spd freewheel. I have read that Campy BB's will work with Superbe, but doesn't that depend on whether it is JIS or ISO. Is there a way to tell is a crank is one or the other, and how can I tell what would be the best spindle length without guessing?

rothenfield1

I just dug up an old C&C BB off and 85 Centurion. Although it is not labeled, it has to be a JP ISO spindle. Probably Sugino. The taper only inserts about halfway into the crank, you can still see prenty of the wear insertion marking on the spindle from where it had been inserted to before. I'm assuming that the JIS taper was a little narrrower allowing the crank to slide all the way to the back of the taper. Seems to prove it is a JIS crank?

HillRider

JIS tapers are actually larger at the end than ISO. They both use a 4° included angle but the JIS starts slightly larger across the flats. It sounds like you installed a JIS crank on an ISO spindle.

DOS

I have been using a Campy BB with an 85 superbe pro for some time with no problems. I don't think my spindle length is quite right ( 114.5mm -- a hair too long) but I think a slight mismatch bewteen the Suntour crank and the campy taper results in cranck seating slightly more inward than it would on a suntour BB so it compensates for the extra length. Anyway, as I said, my mating Suntour crank to the campy GS BB has worked without problem.

A while back I started attached thread to see if I could assertain the truth about Superbe pro spindles. I basically concluded that my 80s Suntour bbs and cranks used a spindle taper somewhere between ISO and JIS based on my experience but that was a wild ass rationalization and mysteries remain.

https://www.bikeforums.net/showthread...gain?highlight=

rothenfield1

Thanks for the responses. I've read enough to roll the dice. I just ordered a relatively inexpensive Campy Veloce cartridge Ital thread 111mm length. We'll see what happens. The Superbe Pro crank, F&R D's are going on an early 80's Rossin if you can imagine that. All the variations between bike components is what keeps me interested in Bike Scientology!!