Shimming 25mm handlebars to a 26mm stem
07-13-20, 10:16 AM
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Shimming 25mm handlebars to a 26mm stem
This may or may not be of interest to anyone, but I recently had to shim a set of older 25mm French handlebars to fit a modern 26mm Nitto stem (part of a LeJeune project that's about done; I will post a few photos by and by). The standard 25.4-to-26 shims were obviously too thin, and I didn't want to go the beer-can route. So I obtained a 25.4 to 26.4 seatpost shim. It fit very nicely into the stem handlebar clamp, allowing me to neatly trace the shape of the clamp area with a fine-point Sharpie.
At only a half-millimeter thick, the material was pretty flimsy, so to cut it neatly I slid it onto a piece of one-inch dowel, taped it in place, and cut along the lines with a jeweler's saw. Cleaned up the cut lines with some fine emery paper, and put it in place in the stem clamp, with the slot in the one-piece shim aligned with the slot in the handbar clamp. Inserted the bars, tightened bolt. It's about perfect--even on minute examination it's hard to see that the bar has been shimmed.
Okay, that's it. I doubt that I'm the first one to do this. It's not rocket surgery, but I thought it was kind of neat.
At only a half-millimeter thick, the material was pretty flimsy, so to cut it neatly I slid it onto a piece of one-inch dowel, taped it in place, and cut along the lines with a jeweler's saw. Cleaned up the cut lines with some fine emery paper, and put it in place in the stem clamp, with the slot in the one-piece shim aligned with the slot in the handbar clamp. Inserted the bars, tightened bolt. It's about perfect--even on minute examination it's hard to see that the bar has been shimmed.
Okay, that's it. I doubt that I'm the first one to do this. It's not rocket surgery, but I thought it was kind of neat.
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07-13-20, 03:50 PM
#3
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That's a small but useful tip for somebody in the future. Sounds simpler, faster and easier than finding correctly dimensioned sheet stock, and then having to roll your own.
07-13-20, 04:17 PM
#4
Senior Member
I may need this in the future if I should build another funny bike. The Scott aero bars have a 25.0 clamp and itd be nice to pair it with a 26.0 stem.
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88' Bianchi Giro. 88' Bianchi Krono. 92' Tommasini Prestige. 80' Gios Torino. 83' Basso Gap
88' Bianchi Giro. 88' Bianchi Krono. 92' Tommasini Prestige. 80' Gios Torino. 83' Basso Gap
Last edited by malcala622; 07-13-20 at 04:51 PM.
07-13-20, 04:45 PM
#5
Senior Member
Originally Posted by jonwvara
This may or may not be of interest to anyone, but I recently had to shim a set of older 25mm French handlebars to fit a modern 26mm Nitto stem (part of a LeJeune project that's about done; I will post a few photos by and by). The standard 25.4-to-26 shims were obviously too thin, and I didn't want to go the beer-can route. So I obtained a 25.4 to 26.4 seatpost shim. It fit very nicely into the stem handlebar clamp, allowing me to neatly trace the shape of the clamp area with a fine-point Sharpie.
At only a half-millimeter thick, the material was pretty flimsy, so to cut it neatly I slid it onto a piece of one-inch dowel, taped it in place, and cut along the lines with a jeweler's saw. Cleaned up the cut lines with some fine emery paper, and put it in place in the stem clamp, with the slot in the one-piece shim aligned with the slot in the handbar clamp. Inserted the bars, tightened bolt. It's about perfect--even on minute examination it's hard to see that the bar has been shimmed.
Okay, that's it. I doubt that I'm the first one to do this. It's not rocket surgery, but I thought it was kind of neat.
At only a half-millimeter thick, the material was pretty flimsy, so to cut it neatly I slid it onto a piece of one-inch dowel, taped it in place, and cut along the lines with a jeweler's saw. Cleaned up the cut lines with some fine emery paper, and put it in place in the stem clamp, with the slot in the one-piece shim aligned with the slot in the handbar clamp. Inserted the bars, tightened bolt. It's about perfect--even on minute examination it's hard to see that the bar has been shimmed.
Okay, that's it. I doubt that I'm the first one to do this. It's not rocket surgery, but I thought it was kind of neat.
Now, if only there were a similar trick to fit 26.0 mm bars into 25.0 mm stems.
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07-13-20, 06:16 PM
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A true craftsman, Jon.
I am too impatient, and go the beer can/utility knife route sometimes even skipping the sharpie step... (This may belong in the confessions thread.)
But now that I know a better way, moving forward, I may have to buy a few shims.
Drat you jonwvara. You've ruined beer can shims (except in emergencies) for me, for ever...
"Drat" was another Dix "ism" I had forgotten - till just now.
Cheers, Eric
I am too impatient, and go the beer can/utility knife route sometimes even skipping the sharpie step... (This may belong in the confessions thread.)
But now that I know a better way, moving forward, I may have to buy a few shims.
Drat you jonwvara. You've ruined beer can shims (except in emergencies) for me, for ever...
"Drat" was another Dix "ism" I had forgotten - till just now.
Cheers, Eric
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Last edited by Last ride 76; 07-13-20 at 06:18 PM. Reason: Correcting the auto-correct...
07-13-20, 10:11 PM
#8
blahblahblah chrome moly
Originally Posted by malcala622
I may need this in the future if I should build another funny bike. The Scott aero bars have a 25.0 clamp and itd be nice to pair it with a 26.0 stem.
That may have been back when Coca-Cola was an official sponsor, so he may have been required to use Coke cans -- no beercan shims allowed!
To Jon V: thanks for the tip, hope I remember it next time I need it!
Mark B in Seattle
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07-13-20, 10:18 PM
#9
Senior Member
Originally Posted by bulgie
Remember when Lemond used Coke-can shims to hold his aero bars in the TdF? I think it was 1989.
That may have been back when Coca-Cola was an official sponsor, so he may have been required to use Coke cans -- no beercan shims allowed!
To Jon V: thanks for the tip, hope I remember it next time I need it!
Mark B in Seattle
That may have been back when Coca-Cola was an official sponsor, so he may have been required to use Coke cans -- no beercan shims allowed!
To Jon V: thanks for the tip, hope I remember it next time I need it!
Mark B in Seattle
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88' Bianchi Giro. 88' Bianchi Krono. 92' Tommasini Prestige. 80' Gios Torino. 83' Basso Gap
88' Bianchi Giro. 88' Bianchi Krono. 92' Tommasini Prestige. 80' Gios Torino. 83' Basso Gap
07-14-20, 01:34 AM
#10
blahblahblah chrome moly
Originally Posted by malcala622
Do I remember?!?!....No not at all I was barely past my first birthday.
-mb
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