Bytesurfer

Does anyone know what the length of the bottom bracket spindle that came in a Fuji 1981 S-12 with a triple chainset?

Thanks.

Bytesurfer

Well, curious if you know what the spindle length of your Fujis (doubles I guess)?

juvela

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might help readers to help you if you could post image of cycle and or chainset

did a check just now and could find no 1981 Fuji catalogues

the classic fuji web site is down/gone


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Bytesurfer

Well I can't post any picture or links just yet since I am still new. I bought the chainset off ebay recently. I asked the seller if he remembered the length of the spindle. He said the bike had been apart for quite a while now. The spindle was pitted thrown away. He thinks it was perhaps around 122mm or 127mm judging by the sunken interface of the drive side crank. So he didn't have an exact answer.

juvela

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you can upload images right away without waiting to make ten posts

there is at your member page here on the forum a place where you can create a photo album

you can upload images there without a minimum post requirement

visitors to you page can put the images into the discussion thread


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AJI125 

Classic Fuji site here: https://classicfuji.posthaven.com/

1981 S12 Triple




Sugino Super Maxy 2D

Starting point at least

Bytesurfer

Ok, I was able to create an album in my account area and added the pictures of the crankset to it. I called the album "Fuji S12 1981 Triple Crankset".

ThermionicScott 

Sheldon Brown’s classic bottom bracket guide: https://www.sheldonbrown.com/bbsize.html

I would start with a 127mm, see how you like the clearances, and go from there. It doesn’t cost a lot to buy a handful of sizes to have on hand so that you can easily check these things. I use any “official” bottom bracket specs as a starting point and usually end up going shorter.

juvela

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thanks very much @AJI125

site was not working when attempted visitation - perhaps a browser issue

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pic assist -

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the stock bottom bracket assembly here is a "Type II" or nutted spindle design

according to Sutherland workable spindles would be model 3T, or if you would like slightly more clearance, model 3U

i would suggest going with the 3U

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Bytesurfer

Thanks, for identifying the assembly. My copy of Southerland is packed somewhere.

So looking online I see in JIS and Clone Spindles for Triple, that the spindle length for a 3T is 126mm. And the spindle length for a 3U is 124.5mm.

juvela

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the copy of Howard here lists the model 3U at 127.5mm in length

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AJI125 

I think someone mentioned Sheldons site already, but note the 3T and 3U are both offset to drive side, so the symmetrical equivalent (if buying most modern options) would probably be longer to get the DS far enough outboard. https://www.sheldonbrown.com/bbsize.html

ThermionicScott 

I see that's a 110mm BCD crank, with all three rings sharing the same bolts. If you wished, you could easily rebuild it as a compact double, which would make sourcing bottom brackets easier.

Bytesurfer

In the version’s chart that I looked at, there was an * by the value of 124.5 for D - spindle length and by the value of 32 for A - left end width. And also on D-3U in bolt-type marking.

The * noted that conflicting manufacturer’s specification, use either 32 or 35mm left end width. So I guess that’s the 3mm difference. The important measure is the right end width which is 40.5mm. All of the center measurement for the Sugino spindles is 52mm.

HTupolev

You can also offset modern cartridge bottom brackets with a spacer on the drive-side cup, especially those that use an unflanged non-drive-side cup.

How would setting it up as a double make sourcing bottom brackets easier?

ThermionicScott 

Bottom brackets in 122-127mm always seem harder to come by than the shorter lengths. Universal Cycles is my barometer for that sort of thing, and they're out of stock. I see on Amazon that there are now a handful of Chinese alphabet-soup brands stepping up to fill the void, though.

Mainly I wanted to put the idea out there since the OP's crank is limited to a 34T smallest ring anyway.

Fibber

Here's an old photo of my S-12S. If I can unearth it, I'll try to pop the crank caps and get you a measurement.

Bytesurfer

That would be great if you could! Knowing the sizes of the left, center, and right sections of the spindle would help too.

Fibber

Last night I tried to do it with the cranks in place, but my calipers won't clear the large chainring and insert into the openings on both sides to get an accurate value. I'll have to get it up on a stand and pull the chainring side off to get you numbers that have any validity. I'm about to send my kid off to college (freshmen), and all hell has broken loose in this household! It may take me a few days to be able to help you.

sd5782 

Not to hijack the thread, but at my local co-op in Toledo Ohio there is a super clean S12S double for sale. Newer panaracers on in and looks like the 23” size. If anyone is nearby, it is $225. I know this bike is desirable for a 650b build, so I would graciously take those 27” panaracers .

Bytesurfer

Ok, sure thing. Thanks.

panzerwagon 

As an extra data point (Fuji-branded double crankset, so not quite what you're looking for), but my S-12 has the original Sugino BB with spindle length of 120mm. Drive side is 35mm and NDS is 30mm, as measured from the outboard ridge on each spindle race.

Bytesurfer

That sounds about right for their Maxy68-W (which is a Super Maxy) was 120mm. Which I figured was for doubles. The Maxy68-T (also Super Maxy) was 124.5mm and that probably is the triple.

I saw this in a Sugino 1978 catalog a few days ago. I will have to post the diagram when I am able.

Phil_gretz

I'd start with the 124.5mm spindle, asymmetric with the drive side 3mm longer.

Bytesurfer

Here is that Super Maxy info from a 78 Sugino catalog I found online. The NJX-2d is the type for the Sugino Fuji from the S-12. And it does seem to use a 124.5mm spindle for the triple. And 120mm for the double.