surreal

i looked at bikeforums' wanted to buy thingie. 3 posts. yeah. does anyone know where i can find a stem that can be crammed into my ancient tange JIS fork? anyone got any lying around?

tia,
-rob

genericbikedude

track stuff. ask in SS/FG

Sheldon Brown

There's nothing "JIS" about stems, no sucha thing.

See: https://sheldonbrown.com/gloss_st-z.html#stem

Sheldon "https://sheldonbrown.com/glossary" Brown

well biked

Your fork might have been on a Schwinn road bike from the '70's or '80's, as many of these bikes had Tange forks and an odd sized inside diameter of the steerer and stem quill (of course, Tange made a LOT of standard-sized 1" threaded forks, also). The inside diameter of the steerer tube would be 21.15 mm, or .833" (usually stamped .833" on the stem), instead of the usual 22.2mm on a 1" threaded fork. As Sheldon says, it's not JIS, but as far as I know on road bikes of this era, they're pretty much "Schwinn specific." The good news is that there are lots of old Schwinns from this time period still out there, and if you look hard enough you can probably find a stem that will fit on ebay. The most common brand of stem used on these bikes were the Japanese-made SR's (LOTS of standard-sized SR's out there, too), and I was able to find one recently on ebay by looking for a distinctive ridge near the top of the quill, where the stem was necked down to the smaller size during the machining process. I kind of think all the stems started out the same during manufacturing, and SR simply machined the Schwinn-specific size down a little more during the manufacturing process. Regardless, the ridge I'm talking about is clearly visible on one of these .833" quill stems, and I've yet to see one that isn't stamped .833" on the lower part of the quill.........if it turns out your fork's not from an old Schwinn of this era, then I have no idea, and disregard everything I've said. Good luck-

surreal

the fork is a tange fork; comes from a nishiki custom sport, with tange infinity tubing. standard 1" threaded stems wont fit. think the 80's-era schwinn ones will?

thanks in advance,
-rob

well biked

You're saying the standard 1" quill stem is too large to fit into the steerer tube?.......If that's the case, then all I can say based on my experience is that a lot of Schwinns of the '70's and '80's had this same situation regarding the stem/inside diameter of the steerer. And most of the forks, maybe all of them, were Tange forks (again, Tange made LOTS of forks, so a lot of them didn't have the odd size I'm talking about). As far as I know, the only other thing that's not standard about the Schwinns I'm referring to is that the large locking nut on the top of the headset assembly will have an inside diameter that matches the .833" stem, in other words it's slightly smaller inside diameter than standard. The threading on the fork steerer, the headset assembly, etc. is all the same as the standard 1" size. I've never heard of bikes other than Schwinns using this odd size, but that doesn't mean it's not so, of course...........Is it possible a fork off of a Schwinn was put on your Nishiki?

HillRider

A couple of ideas:

1. Is the steerer interior very rusty or dirty? Maybe a cleanup will let the stem fit if the steerer has a lot of built-up crud inside.

2. You could sand a standard stem quill down to fit. You only have to remove a very small amount of material so this is a safe approach.

Sheldon Brown

I too have not heard of .833 forks being used on road bikes other than Schwinns, but this size was also quite common on early mountain bikes, late 1970s and early '80s. The early MTBs were heavily influenced by the Schwinn Superior "klunkers" that preceded them, hence the use of the .833 forks.

We've got some stems: https://harriscyclery.com/opc

Sheldon "https://sheldonbrown.com/cribsheet-headsets.html" Brown