sd5782 

After some searching I found on eBay a vintage SR stem listed as 22.2 and I purchased it. Upon receipt it is marked with a marker as 22.0 and measures just under 21.9. I wanted the stem because it was a bit taller than usual, but was listed as the standard 22.2. So, a bit over .2mm. It of course went right in and only was a slight bit looser than the others.

I did some searching about advice on this discrepancy but saw little. I got out a bunch of old stems that were mostly around 22.1. One aftermarket one was a bit under 21.8 and not French. I saw some advice about shimming, but .02mm was the thickness of 2 pieces of paper. If I wouldn’t have seen the writing in marker on the stem I would have had blissful ignorance. I’m probably going to use it and forget about it. Tell me why not, but not too forcefully.

SurferRosa

I've done this before, and it was a keeper bike, which didn't really give me the warm fuzzies. My biggest issue is the need to tighten down the expander/wedge bolt super tight, which isn't the proper way to do it at all. But I never had a problem with it.

thook

I haven't had to do this, but if I were to do it I'd find something to shim the quill inside the steerer (very thin aluminum...maybe a soda can?) and use an wedge meant for a 22.2 steerer/stem. The shim is only there to keep the quill from wobbling about while the wedge, of course, tightens it up.

Bobjackson

This is how you do it in the machine shop world. The interference clearance is twice the thickness of the shim on the shaft.

Stainless Steel Shim Stock, Unpolished (Mill) Finish, Full Hard Temper, 0.004" Thickness, 6" Width, 50" Length https://www.amazon.com/dp/B0002FSV7C...BXB2H2SQR9F2BD

bulgie 

Tight at the bottom and loose at the top annoys me, but maybe it's not a real problem, I'm just such a princess that I'd notice a pea stuck in my steerer?

Generally speaking the more expensive a stem is, the closer it is to 22.2 mm. Tolerances are all on the minus side, because they need to ensure the stem will go in without binding. Being a bike snob I've mostly gravitated to high-end stems. I do notice the extra wiggle when I ride a bike with an undersized stem, but maybe I'd get used to it and stop noticing after a while?

The movement at the handlebar is increased by a taller stem, and by wider bars. Also theoretically you'll get more movement at the bars if you have less insertion in the steerer. A stem that's "slammed" will have the same 0.2 mm of slop right at the top of the steerer, but it translates into more motion out at the ends of the handlebar, because geometry.

Overtightening to compenstae is safer with a wedge-type than with a cone. I assume your SR is a wedge, amiright? Careful, it is possible to damage the steerer, making a permanent bulge in the tube from overtightening, even with a wedge. Hard to know what torque that requires until you exceed it, but ya gots to have the stem anchored to where it won't move while riding, so that's your floor, torque-wise. Hopefully (usually) there's a range between tight enough and kablammo.

Mark B

sd5782 

I have a bunch of shim stock, but was a bit reluctant to use knowing it could drop down easily even when making adjustments without remembering it is in there. The wedges I measured that I have are all over the place too. Interestingly, a Peugeot 22.2 is the only one I have that measures at 22.2. The wedges obviously make a bind at the top as well as the bottom, as we all have scarred stems to prove it.



80mm by 185 long





I think I will just use one of the very slightly wider wedges I have, and ride in bliss and forget about it. As I said, I wouldn’t even have measured or even noticed anything amiss if I didn’t see a marker notation on it. Thanks

DiegoFrogs

Perhaps you could trade with someone looking for a stem for a French bike?

sd5782 

What a crazy thought. Yes, practical but then there is another $10 shipping.

bikemig 

What about the clamp dimensions? If this stem is designed for a French bike isn't the clamp size likely to be 25.0?

https://www.sheldonbrown.com/cribsheet-handlebars.html

DiegoFrogs

Sadly, this Toledo dweller has no French bikes and doesn't have the space to store another bike, so I'm no help there.

sd5782 

Stem clamped very nicely on a 25.4 bar.

wrk101

I've got an SR stem I just pulled off a 1976 Motobecane. Clearly marked 22.00. The handlebars I removed had a clamp area OD of 25.4mm and they removed without a problem.

I've been recommending late 1970s Motobecanes as french donors for years. The same bike had Tange branded Swiss BB cups, Suntour V GT Luxe RD, and more.

Sir Sheldon was wrong about this one.

repechage

I do not like shims
I do not like creaks

BFisher

That crib sheet makes no claim on the correlation of quill size to clamp size. That's a handlebar dimension crib sheet.

BFisher

@sd5782, the stem you show is factory stamped "22.00" but suffers from an incomplete strike. It's visible to the left of where the size was written in black marker.

If it was me, I'd seek the stem size that matches the steerer tube. Why not?

sd5782 

I see that partial mark now. I haven’t seen a taller vintage stem like this except in a 60mm. I haven’t been looking for long, so maybe they are out there. Of course, the Nitto Technomic is available, but I didn’t really want something that new on this 72 Fuji project. I have somehow come into 3 of the 60mm extension versions of this stem but wasn’t having luck with an 80 or 100. I will put it on and report back on a ride after the snow melts. It actually doesn’t feel sloppy upon installation, and snugs up just like the ones marked 22.2. As I mentioned the difference is .008” and we aren’t talking a precision application like bearing tracks or such. The seller did misrepresent it, but it suits my needs and it would be a pain to return.

TPL

Simple fix = get a 22.2 stem

zandoval 

Many, many times I have used aluminum beer can material as a shim. Some times I don't even need to wrap it fully around the needed diameter. Do note that when I have used beer can shims the aluminum is so soft that it can eventually squeeze out under forced pressure. Not a big problem as I just replace the shim with another as it is an infrequent occurrence.

Finding odd ball or miss sized internal and external diameters on vintage bikes is not a big surprise. Often these older bikes have been miss used or have had parts forced onto them. As you know, remember to check the hole first. I have been humbled by this fact.

DiabloScott

I did this once on an old beater Peugeot - 22.0mm stem in a 22.2 mm steerer.
It wiggled around a little bit, and probably a little more rain got in there, but it was safe, and it wasn't a big deal... for a beater Peugeot.

oneclick 

What you do is fold the top 1/8" of the shim over before you curve it around the stem - fold twice if it's not thick enough. This gives you a rim at the top of the shim.

If the shim is thick you can just fold it over 90 degrees and you get a lip; best to do this after installing, get the shim the right amount proud and use a thin blade to start working it over.

sd5782 

Thanks for all the input folks. I believe I will reach out to the seller first and then probably shim it if I do wind up using it.

wrk101

OK, how about this one?

https://www.sheldonbrown.com/velos.html

BFisher

True, but that's a Japanese stem, not a French one. I suspect, but obviously can't confirm, that when they started sourcing from Japan, matching their steerer dimension was the bigger concern. All of the French made stems I have had - Pivo, Ava, Belleri France, etc. - were 25.0.

sd5782 

I did more stem searching and couldn’t find a 180 tall vintage in any length except 50 and 60. Actually I was a bit surprised I found the one I bought. I was running an inexpensive Kalloy/Origin8 with the 80/180/22.2 dimensions on my vintage Trek for a couple years. I just took that stem off and put a dirt drop riser bar on the Trek for this old guy. Interestingly the Kalloy stem diameter measured the same as this 22.0 stem I just got.

So, taking the advice from some here, I got out some steel shim stock of .005”. That was too thick. I did use some that was .003”. Insertion was about 3.25” on the shim and it pretty much is 95% of the diameter. The stem is now perhaps my one with the least slop. Hey, it’s winter and I am retired so time to mess with things until the snow melts




The Nitto Technomic for old guys would have been the easier choice, but I wanted something a bit more vintage looking.




The stem is at the top of adjustment in photo, but still extends down past the top tube as it is perhaps 7.25” long. My shim inserts perhaps halfway down the head which seemed fine. The job wasn’t too hard to do.

BFisher

That's a nice looking Fuji!