21.1mm stem for French steerer?
09-03-21, 05:51 AM
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21.1mm stem for French steerer?
I've a Peugeot that takes a 22mm stem. It currently uses a 22.2mm gooseneck stem that's been sanded down and it sort of fits -- but it's really tight, fitting just barely down to the minimum insert line, and I'd like to have something that fits a little nicer in the steer tube (so I can adjust it up and down as needed, etc.). Could I safely use a 21.1mm stem that has the ramped wedge (vs. the expanding conical wedge)?
(I do have the original stem, but I'd rather use a stem with a 25.4mm clamp size for the most compatibility with handlebars.)
(I do have the original stem, but I'd rather use a stem with a 25.4mm clamp size for the most compatibility with handlebars.)
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09-03-21, 06:23 AM
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22.0mm Stems
The French/Metric standard for stems was 22.0mm. Exception, Cinelli, 3TTT and some other manufacturers made stems that WERE 22.0mm.
Problem: You can't put a stem that measures 22.0mm into a steerer that also measures 22.0mm.
Reality: many metric stems were 21.9mm to allow for some clearance. Steerers were usually but not always slightly oversize too.
Solution(s): For starters, I'd thoroughly clean out all of the gunk inside the steerer with a liquid cleaner or solvent. Next, run a hone (if you have one) down the steerer to clean up any corrosion and burrs or seams inside. Also make sure the opening in the headset top lock nut is large enough - screw it on and test the fit of the stem. Threads on steerers were frequently off center enough so the lock nut would be slightly misaligned when tightened.
No hone? No problem. Roll up some 100 to 120 grit abrasive cloth or wrap it around a wooden dowel and manually use it as a hone. The smooth ID makes assembly and adjustment easy. I slightly chamfer the inside of the steerer too. Helps ease insertion. While you're at it, do the same thing to the seat tube.
Next, most of the Nitto stems that I've measured, while marked 22.2mm are actually 22.1mm and fit in many metric steerers with little or no problem.
Last thing, when installing the stem, coat the quill and inside of the steerer with lots of grease! Prevents stuck stems!
As far as a 21.1 stem, I wouldn't recommend it. For one thing, it will probably creak a lot. Tightening it down enough can bulge the steerer too. The only stems that size that I've seen were low quality found on cheap bikes.
One more last thing, I'd suggest pulling the fork and checking the threads. Many manufacturers used CHEAP steerer tubes, even on high end models made of Reynolds or Columbus tubing.
Make sure that the stem is inserted at least 75mm-80mm (3") into the steerer. If a stem is expanded into the threaded area it can bulge them and leads to catastrophic failure.
Bulged threads
Opposite side - note split in the flatted area and crack forming in the threads.
25.0mm bars were somewhat of a standard on French bikes.
verktyg
Problem: You can't put a stem that measures 22.0mm into a steerer that also measures 22.0mm.
Reality: many metric stems were 21.9mm to allow for some clearance. Steerers were usually but not always slightly oversize too.
Solution(s): For starters, I'd thoroughly clean out all of the gunk inside the steerer with a liquid cleaner or solvent. Next, run a hone (if you have one) down the steerer to clean up any corrosion and burrs or seams inside. Also make sure the opening in the headset top lock nut is large enough - screw it on and test the fit of the stem. Threads on steerers were frequently off center enough so the lock nut would be slightly misaligned when tightened.
No hone? No problem. Roll up some 100 to 120 grit abrasive cloth or wrap it around a wooden dowel and manually use it as a hone. The smooth ID makes assembly and adjustment easy. I slightly chamfer the inside of the steerer too. Helps ease insertion. While you're at it, do the same thing to the seat tube.
Next, most of the Nitto stems that I've measured, while marked 22.2mm are actually 22.1mm and fit in many metric steerers with little or no problem.
Last thing, when installing the stem, coat the quill and inside of the steerer with lots of grease! Prevents stuck stems!
As far as a 21.1 stem, I wouldn't recommend it. For one thing, it will probably creak a lot. Tightening it down enough can bulge the steerer too. The only stems that size that I've seen were low quality found on cheap bikes.
One more last thing, I'd suggest pulling the fork and checking the threads. Many manufacturers used CHEAP steerer tubes, even on high end models made of Reynolds or Columbus tubing.
Make sure that the stem is inserted at least 75mm-80mm (3") into the steerer. If a stem is expanded into the threaded area it can bulge them and leads to catastrophic failure.
Bulged threads
Opposite side - note split in the flatted area and crack forming in the threads.
25.0mm bars were somewhat of a standard on French bikes.
verktyg
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Don't believe everything you think! History is written by those who weren't there....
Chas. ;-)
Last edited by verktyg; 09-03-21 at 06:45 AM.
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09-03-21, 06:45 AM
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Thanks, to both of you. The stem I have in it now looks like a Nitto dirt drop style stem. I don't know if it actually is that brand, but I will say that stem does fit better than others I tried -- it's just very tight still. The hone's a good idea (inside the steerer). I do acknowledge that the 21.1mm stem would probably creak, and might be more trouble than it's worth.
And you're right about the top lock nut -- it's not bad, but it's also not centered exactly...creating some interference with the stem. I'll take all this as a winter project and get that sorted out (this is on a bike that I don't ride often).
And you're right about the top lock nut -- it's not bad, but it's also not centered exactly...creating some interference with the stem. I'll take all this as a winter project and get that sorted out (this is on a bike that I don't ride often).
09-03-21, 09:34 AM
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The Origin8 Classique stem is sold as a 22.2mm quill, but in my experience with two bikes that have French 22.0mm steerer tubes, the stem fits without modification. I’ve heard this can also be true for Nitto stems, but I’ve never tried it with Nitto.
https://www.ebay.com/itm/17492220057...MAAOSwI~thMjxZ
https://www.ebay.com/itm/17492220057...MAAOSwI~thMjxZ
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