21.15mm stem in 22.2mm Steerer Tube. Shim or no shim?
02-01-24, 03:34 PM
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21.15mm stem in 22.2mm Steerer Tube. Shim or no shim?
Hey, folks! I recently swapped out a threaded 1" fork on a bike, with the new threaded 1" fork having a 22.2mm steerer tube. Unfortunately, the original stem on the bike (and original steerer tube) were 21.15mm, which leaves a very minor amount of room around the original stem once inserted into the new steerer tube. I'd really like to keep the original stem. When inserting the original stem into the new steerer tube, the wedge tightens down normally (apparantly) and everything seems firm with no perceptible flex or anything. I can throw a Coke-can style shim in there to fill the gap, but if everything seems to be fine, do I really need to?
Thanks much in advance!
Joe
Thanks much in advance!
Joe
02-01-24, 05:01 PM
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Just get the right sized 22.2 stem. They are so common that there is no reason to make do with an undersized stem.
You don’t want to risk having the stem loosen on you in the middle of a ride.
You don’t want to risk having the stem loosen on you in the middle of a ride.
02-01-24, 09:41 PM
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Hey, folks! I recently swapped out a threaded 1" fork on a bike, with the new threaded 1" fork having a 22.2mm steerer tube. Unfortunately, the original stem on the bike (and original steerer tube) were 21.15mm, which leaves a very minor amount of room around the original stem once inserted into the new steerer tube. I'd really like to keep the original stem. When inserting the original stem into the new steerer tube, the wedge tightens down normally (apparantly) and everything seems firm with no perceptible flex or anything. I can throw a Coke-can style shim in there to fill the gap, but if everything seems to be fine, do I really need to?
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02-02-24, 12:23 AM
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It's not absolutely necessary to shim it, since the wedge usually has plenty of travel. Sometimes the wedge runs out of travel before being tight, but that can be fixed with a file.
OTOH you might prefer to shim, because while the wedge braces the bottom, the top is free to rock back and forth.
It's not necessary to shim the full length, just up near the top.
How you shim is up to you, and may depend on how deep the stem is. Also, do not shim the area near the wedge. I'm partial to gummed paper tape, because it's easy to widn to an exact diameter. Once it's assembled, soak oil in, and the oil soaked tape will outlast you.
OTOH you might prefer to shim, because while the wedge braces the bottom, the top is free to rock back and forth.
It's not necessary to shim the full length, just up near the top.
How you shim is up to you, and may depend on how deep the stem is. Also, do not shim the area near the wedge. I'm partial to gummed paper tape, because it's easy to widn to an exact diameter. Once it's assembled, soak oil in, and the oil soaked tape will outlast you.
Last edited by FBinNY; 02-02-24 at 12:27 AM.
02-02-24, 02:44 AM
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Hey, folks! I recently swapped out a threaded 1" fork on a bike, with the new threaded 1" fork having a 22.2mm steerer tube. Unfortunately, the original stem on the bike (and original steerer tube) were 21.15mm, which leaves a very minor amount of room around the original stem once inserted into the new steerer tube.
Joe
Joe
Fortunately, this was a common occurrence years ago so there’s a shim made just for this purpose:
https://www.amazon.com/Wald-905-Stee.../dp/B000A5QDY2
A bike shop that’s been around for a few decades might have these in stock.
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02-02-24, 09:04 PM
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That’s a 1 millimeter difference in diameter… not “minor”. The handlebars will rock side to side, which can be unpleasant.
Fortunately, this was a common occurrence years ago so there’s a shim made just for this purpose:
https://www.amazon.com/Wald-905-Stee.../dp/B000A5QDY2
A bike shop that’s been around for a few decades might have these in stock.
Fortunately, this was a common occurrence years ago so there’s a shim made just for this purpose:
https://www.amazon.com/Wald-905-Stee.../dp/B000A5QDY2
A bike shop that’s been around for a few decades might have these in stock.
For those like me who prefer an alternative to Amazon: https://www.porkchopbmx.com/wald-905...g-shim-13.html
(cheaper too!)
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