Gorillalove

Hello. I picked up an unknown frame for cheap and I want to make it a single speed. The SR stem I bought is a tad too big to fit. Are there different stem diameters? If you can point me in the right direction that would be great. Frame has been painted over so I haven't the foggiest as to who made the frame.

due ruote 

Probably a French frame. Or at least the fork. You can sand down the quill to fit, or look for a French one, which will be 22.0 instead of 22.2 mm diameter.

Also be aware the bottom bracket likely has French threading, or maybe Swiss.

Gorillalove

Thanks for the answer.

Kuromori

Assuming you don't have a 25.4mm stem for a 1 1/8" steerer, you might also have a Schwinn or other American bike that uses slightly different sized stem which is between French and English.

SurferRosa

Use 80 grit paper on it for a few minutes.

When it's close to fitting, switch to 600 grit.

PilotFishBob 

Check Sheldon's page on French bikes - assuming that's what you have it can be a useful source of info for you.
https://www.sheldonbrown.com/velos.html

BradH

Some Schwinns had 21.1mm/.833" stems.

TenGrainBread 

Post pics of the frame and we can identify possibly.

dddd

Many low-end Nishikis and other brands, as well as American bikes, used the much-smaller 21.1mm or .833" quill diameter which allowed a cheaper, thicker-walled, straight-gage steer tube to be used.

You won't be able to "sand down" a normal 22.2mm stem quill to fit such a fork steerer.
You might even find a hard time trying to sand down a 22.2mm stem quill to fit a 22.0mm French or Austrian steer tube I.D., as many stems show a material resistance to sanding that is quite impressive. For such stems, I have used a file, starting near the bottom of the stem quill and working my way up after successive test-fits until the needed amount of insertion is achieved.

Modern Kalloy road stems (also sold under "Origin8" branding) are specifically sized to work well in either 22.2mm or 22.0mm fork steerers, and I would say that they did their research in terms of "hitting the numbers" that work well in the real world as a reliable connection.
These stems are offered in 25.4mm and 26mm clamp sizes, and are most economical and sturdy, if a bit on the chunky side for an alloy stem.
Pictured below on a 1968 SEARS/Steyr with Origin8 brand logo removed using fine steel wool that left no scratches at all:

79pmooney

I use 220 emery cloth. Takes longer but with the cloth you cvan do a better job. The 600 at the end is optional dependent on how much looks matter to you.

Gorillalove

It has a 26.4 seat post. Does that narrow down it being a French frame? Are french BB available here in the states

unworthy1

Yes, with 26.4 more likely now a FR (metric) seat tube so if fork matches frame you likely need a 22.0 stem rather than the slightly harder to find 0.833" but use a digital caliper and make several measurments bofore you buy a mew one, of borrow a FR stem and test-fit (more reliable). Or just sand down a 22.2 until it slides in.
Yes for NEW FR sealed BB check out Velo Orange or just ask here in ISO WTB thread or try eBay for other (used) options.

Gorillalove

Thanks

Gorillalove

Just figured out the quill I took off of it is a Schwinn with what I believe to be a 21mm diameter.

unworthy1

OK, then scratch my comment about it being FR and 22.0, you can find the smaller 0.833" quills but they are fewer and far between for vintage road bikes (Schwinn and several Asian brands used them, maybe Nishiki was the next biggest brand to spec those on SOME models) but many BMX bikes that use a quill stem come with 21.1mm

Ex Pres 

Are we making the assumption that what was in there was correct? Someone along the line could have used an .833 because it's 22.0 and the 22.2 stems they had didn't fit.

noobinsf 

Agreed - I once bought a Peugeot UO-8 frame that came with a Schwinn stem. It “fit,” but it wasn’t the correct fit. Pics would help...

unworthy1

"WE" sure are assuming that, so...you know what they say about ass-uming! I will step away from the thread and let cooler heads prevail.

Kuromori

If it fits easily and isn't undersize, then it fits. Obviously one too big won't fit, and there are concerns about stems too small because some (AVA) of them have designs prone to cracking and the interface is worse. I can not think of a good reason to not use a stem even if it is slightly larger than what the standard calls for if it still slips in easily.

cudak888 

Have we also ascertained for certain that that there isn't an incorrect 0.833 headset nut on the fork?

Just trying to cover all bases here.

-Kurt