daveed

I recently refurbished (with a spray paint can) an old mtn bike frame of uncertain vinatage. When I dropped the 1" stem from a newer bike into the head tube -- surprise! -- it was too big. I looked at the measurement: 22.2.mm. I've since learned that some bikes once came with 22.0mm steerer tubes. I bet that's what I need. Can one easily find 22.0 stems or will I have to switch forks to use the stem I want?

Thanks.

well biked

I was thinking you might have a JIS headset/fork/headtube on the bike, but after thinking about it, it's probably that you have a 21.15mm inside diameter on your fork steerer, and you need a stem that's sized for that as well. Not uncommon on very old mtb's. The lock nut on the headset will also be sized for 21.15mm (the inside diameter of the nut where it fits snugly around the stem).

daveed

Thanks for the info, well biked. Funny, I put a new Tange replacement headset on the bike. Didn't change the cups, but everything else, locknut included. And it all seemed to fit (so far). Didn't bother measuring, tho, just screwed the parts on and tightened. Gave the old parts away.

Can you guess-timate how old this bike is given its steerer tube diameter? It has no markings. It's set up for cantis and has no derailer hanger on semi-hrizontal drops, tho it has cable routing bosses. Tig-welded joints, not lugged. Steel, of course.

well biked

Impossible to say about the age from that info, especially since mtb's were often welded construction before it became more common on road bikes. 21.15 mm is the old Schwinn standard, common on a lot of their older bikes. It goes back to some of the Schwinn "clunkers", which in modified form were the original mtb's. Apparently, some very early mtb's (maybe even some later ones, I don't know) kept the 21.15 mm standard as a holdover from the Schwinn clunkers. I've had several old Schwinn road bikes that used this size, but it was Sheldon Brown who pointed out not long ago that it was a holdover on some of the old mtb's as a result of the sizing on the Schwinn clunkers-

moxfyre

JIS headsets work with standard sized 1" quill stems (22.2 mm). I think the 21.15 mm size (old Schwinn size) is more likely to be correct! I believe that many department-store bikes still use that size, so you might be able to get a stem off a junked Magna or Huffy (though not a very nice stem ).

well biked

Yeah, I realized that and changed my mind with my answer to the OP, deciding it's more than likely the 21.15mm (.883") stem issue I've run into a few times myself.............To the OP regarding the age of your bike: if you think it has some original components on it, you can go to www.vintage-trek.com and after finding the date codes that are stamped on the components, you should be able to find info on the site that will give you the components' age. They've got info on Suntour, Shimano, Sugino, etc.

daveed

Thanks to both of you for the illumination. There were no original parts on the bike when I came acorss it a few weeks ago. I liked the shape of the frame, got rid of the old components (except for the double walled Mavic rims) and painted (Rustoleum's "hammered finish" -- quite nice, actually). Other than the BB's long serial number, there's nothing to give away the rig's provenance other than a pseudo "lug" on the seat tube just below the seat itself.

BTW, I just did find an alloy quill stem -- adjustable!-- that fits the headtube. It looks a only a tiny bit weird, honestly.

moxfyre

Photos?

What kind of stem is it?

daveed

I'd LOVE to send you pictures. I've just taken 'em. But how the heck do you go from 1.28MB to the size required by this site? They pics are on the computer but they won't attach to this reply.

The stem in any case, the stem is newish. I don't know the make because a friend brought it over and he has no idea where or when he got it. The device features degree markings (from 10 to 50) along one side. Two bolts secure the bar; a bolt on the underside loosens the moveable top portion -- somewhat like a seat post (an old SunTour double bolter, for example).

I dropped the stem in and hooked up the short front brake cable. I can't pull it all the way to see its markings without disassembling the cable yoke that's attached to the headset. Obviously, I didn't look in the first place.

moxfyre

Daveed, generally the easiest way to reduce a photo's file size is to resize it. In Windows, you can open the photo in Paintbrush and then shrink it down to about 400x300 and then save it as a JPEG. That should fit in under the 100k limit for Bikeforums.

Under Linux, I just type the command "convert -resize 400x300 photo.jpg smaller.jpg", and that does the trick

daveed

I think I attached the stem, Mox, that is, if you are still (virtually) here. Thanks for the instructions.

moxfyre

Well, that does indeed look like a modern adjustable stem of a decent quality... pop-top and allen bolts and all that. I wonder where it came from. Well, glad you found something that works

daveed

I'm practically giddy having learned how to "upload." Here's another shot of the stem that fits the 21.15 (?) head tube.

well biked

Can you put up a pic of the whole bike?........If the quill size on the stem is 21.15mm, that equates to .833", or approx. 7/8" btw. The older stems I've seen that use this standard are usually stamped .833". Glad to see you got something that fits-

oilman_15106

If you find that it is the old Schwinn size PM me and I can put you in touch with a shop in our town that has a ton of older stuff in stock. I got a Schwinn, early 80s, frame to build up for someone else with the smaller 1" and they came up with a fork and headset to work with it. Good luck.

daveed

If Ihave time I'll yank the stem and have a look at the numbers. Meantime thank you for your help -- and thanks to Oilman, too. I'd like to know the name of the shop with the old parts. Btw, that old Avocet saddle is VERY uncomfortable.

CyberDaug

That Stem looks like the one that came on my Trek Navigator.

Danwi

Dude I wish I knew where that stem came from as I really need one!

Danwi

I need a stem like that!