[bwana]

After a few weeks of watching and bidding, I bought a Sugino Super Maxy 110 BCD crankset off of ebay. I currently have a Sugino Super Mighty 144 BCD but wanted a smaller inner chainring to keep my knees happy. I figured that being the same manufacturer and roughly the same vintage that there would be no problem, but of course the new one tightened up with the inner chainring stuck against the chain stay. I'm guessing that the Super Maxy is a JIS and the Super Mighty is ISO? I'm know that JIS bottom brackets aren't widely available anymore, and I know that finding spindles is almost as hard as finding new hoods for my Gran Compe brakes, so can I just go with a wider ISO cartridge bb?

 

[FatTireFred]

After a few weeks of watching and bidding, I bought a Sugino Super Maxy 110 BCD crankset off of ebay. I currently have a Sugino Super Mighty 144 BCD but wanted a smaller inner chainring to keep my knees happy. I figured that being the same manufacturer and roughly the same vintage that there would be no problem, but of course the new one tightened up with the inner chainring stuck against the chain stay. I'm guessing that the Super Maxy is a JIS and the Super Mighty is ISO? I'm know that JIS bottom brackets aren't widely available anymore, and I know that finding spindles is almost as hard as finding new hoods for my Gran Compe brakes, so can I just go with a wider ISO cartridge bb?

what do you mean "the new one tightened up with the inner chainring stuck against the chain stay"?? spindle too short?

 

[bwana]

I used the current spindle, and the Maxy crank went farther onto the spindle than the Mighty crank does. Also true for the non-drive side. Reading the late Sheldon Brown's piece on JIS vs ISO cranks, a JIS crank will mount about 4.5mm further in on an ISO spindle than an ISO crank would, and and ISO crank will mount about 4.5mm further out on a JIS spindle than a JIS crank would. He also claimed that while mfgrs wouldn't recommend it, he had mixed and matched JIS and ISO successfully.

 

[Slow Eddie]

I think the crux of the problem is trying to determine whether it's a JIS vs ISO issue or just a spindle length issue.

FYI, ISO tapered BB's are produced mainly by Campy. I believe Phil Wood, Miche, and Token are other sources that currently produce ISO tapered BB's.

My understanding was that you could pretty safely generalize that if the company was japanese and started with an "S" - Shimano, Suntour, and Sugino immediately come to mind - that the cranks and BB's used a JIS taper.

If the Maxys have a 110 BCD, are they meant to be a triple? (not being wise; I'm answering off the cuff and haven't looked these cranks up) If so, they might want a longer spindle than a double crank of the same era.

 

[Dave Hickey]

I think the crux of the problem is trying to determine whether it's a JIS vs ISO issue or just a spindle length issue.

FYI, ISO tapered BB's are produced mainly by Campy. I believe Phil Wood, Miche, and Token are other sources that currently produce ISO tapered BB's.

My understanding was that you could pretty safely generalize that if the company was japanese and started with an "S" - Shimano, Suntour, and Sugino immediately come to mind - that the cranks and BB's used a JIS taper.

If the Maxys have a 110 BCD, are they meant to be a triple? (not being wise; I'm answering off the cuff and haven't looked these cranks up) If so, they might want a longer spindle than a double crank of the same era.

What he said..This sounds more like a spindle length problem.....not a jis/iso issue

 

[bwana]

Well, okay, but the left arm also mounted much farther inboard than my current left arm does.

 

[dmar836]

Not the wrong offset, the wrong length. You need a spindle that is longer and sits out further on both sides, cartridge or otherwise. Good luck.

 

[curlybike]

If the spindle length is the same it is a JIS/ISO problem, and if you look carefully you will find the the end of the spindle is flush with the interior surface of the crank arm where the washer hits. Therefore just buying a JIS spindle that is 10 mm longer will not solve all your problems. The Sugino Mighty is a match for Campy and not JIS as per Sutherland #6

 

[dmar836]

So Sheldon is right. You have an JIS Maxy on an ISO spindle. Would adding an effective 4.5mm on each side fix your clearance problem? You could go with a cheap Shimano JIS cartridge of the same width which would give you that 4.5mm on each side.
Or am I missing something?

 

[bwana]

I think what I'll end up doing is re-selling the Super Maxy, and look for a complete bb/crankset. Thanks to everyone for your responses.

 

[curlybike]

So Sheldon is right. You have an JIS Maxy on an ISO spindle. Would adding an effective 4.5mm on each side fix your clearance problem? You could go with a cheap Shimano JIS cartridge of the same width which would give you that 4.5mm on each side.
Or am I missing something?

Yes, you are! Frequently the washer under the Crank Bolt or the Crank nut will bottom out on the end of the spindle before the arm is tight on the taper. This leaves you eventually with a loose arm and it will probably fail or be ruined because of that.

 

[dmar836]

I have always avoided mixing them for that reason. The difference is apparent when fitted side by side. I was referring only to the 4.5mm clearance issue created but mixing the two(which the OP considered doing)... taper problems aside. Makes one wonder why Sheldon would say this. He seemed fairly anal and not too hack-like.

 

[curlybike]

You can make the arm tighten up ok, if you shorten the spindle by grinding some off of the end of the spindle, so that nothing touches the end when the arm finally gets tight. It is a hack way to do it, but it works.