Using a 26mm bar with a 25.4MM stem?
02-06-08, 11:53 AM
#2
Pwnerer
No.
OK, no with a few caveats:
Yes, it may be possible to wedge the stem apart far enough to get the bars in, but in doing so you are compromising the strength of the material as well as putting uneven pressure around the circumference of the bars. Even if the stem has a removable faceplate, you will still only be clamping the bar at certain points. With a carbon bar this could be disastrous, with a steel bar it may be fine.
The bottom line is that parts that were designed to work together will give the best performance. Anything else is a kludge and at your own risk.
OK, no with a few caveats:
Yes, it may be possible to wedge the stem apart far enough to get the bars in, but in doing so you are compromising the strength of the material as well as putting uneven pressure around the circumference of the bars. Even if the stem has a removable faceplate, you will still only be clamping the bar at certain points. With a carbon bar this could be disastrous, with a steel bar it may be fine.
The bottom line is that parts that were designed to work together will give the best performance. Anything else is a kludge and at your own risk.
Last edited by Wordbiker; 02-06-08 at 12:01 PM.
02-06-08, 12:01 PM
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Whoops- edit.
No.
Whoops again-
I've seen 26 bars stuck into 25.4 wrap-around stems so it's possible, but if you have a pop-top stem, no.
No.
Whoops again-
I've seen 26 bars stuck into 25.4 wrap-around stems so it's possible, but if you have a pop-top stem, no.
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02-06-08, 12:05 PM
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Anybody know where to find a 26mm stem? All I can seem to find is 25.4. I have a couple of 26mm bars laying around that I want to use.
02-06-08, 12:33 PM
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I don't see any problems making the stem hole a little bit wider by using a round file.
The opposite thing is more difficult because you have to use shims.
The opposite thing is more difficult because you have to use shims.
02-06-08, 01:07 PM
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Quill or threadless?
If you're looking at threadless you may be confusing the bar clamp with the stem clamp diameter.
Most of the European quills (save some Cinelli) are 26.0mm. Japanese have a lot of 25.4 so you need to check.
If you're looking at threadless you may be confusing the bar clamp with the stem clamp diameter.
Most of the European quills (save some Cinelli) are 26.0mm. Japanese have a lot of 25.4 so you need to check.
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02-06-08, 01:22 PM
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02-06-08, 01:59 PM
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Most threadless road stems are either 26.0 or 31.8, so you have a lot to choose from. Don't confuse bar clamp with the stem clamp diameter, either 1" (25.4) or 1 1/8" (28.6)
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02-06-08, 02:00 PM
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I think you've got that backwards. Pop-top stems are much more forgiving, they clamp the stem between two plates versus the bending and pinching action of a quill.
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02-06-08, 02:42 PM
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Originally Posted by Sheldon Brown
"Pop top" type stems use two bolts and a removeable faceplate to hold the handlebar. This offers a number of advantages:
- Since it doesn't work by flexing the aluminum as a single-bolt stem does, they're less fussy about bar diameter, so the same stem can generally be used for 25.4 or 26 mm handlebars
02-06-08, 02:44 PM
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That being said, I'd look closely before installing. I'm running a 26mm moustache handlebar knock-off in a high-rise MTB 25.4mm stem, and there wasn't a noticeable gap at the front of the pop top face plate.
02-08-08, 08:51 PM
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This thread and others like it made me paranoid about my 26mm bars in 25.4mm stem. So I did a little test last night. I took the handlebar out of the stem, then I took the face plate of the stem and put it around the bar. At the position it was installed, the face plate and bar had the same curvature, but when I slid the face plate around the bar 90-degrees, there was a huge gap between them. Essentially, the stem ovalized the bar by pinching it at the edges of the stem and face plate.
Today, I installed a new 25.4mm handlebar and will be tossing the 26.0mm bar as I am not confident of its integrity anymore. Costly mistake, but not as much as an uninsured crash.
Today, I installed a new 25.4mm handlebar and will be tossing the 26.0mm bar as I am not confident of its integrity anymore. Costly mistake, but not as much as an uninsured crash.
02-08-08, 08:54 PM
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This thread and others like it made me paranoid about my 26mm bars in 25.4mm stem. So I did a little test last night. I took the handlebar out of the stem, then I took the face plate of the stem and put it around the bar. At the position it was installed, the face plate and bar had the same curvature, but when I slid the face plate around the bar 90-degrees, there was a huge gap between them. Essentially, the stem ovalized the bar by pinching it at the edges of the stem and face plate.
Today, I installed a new 25.4mm handlebar and will be tossing the 26.0mm bar as I am not confident of its integrity anymore. Costly mistake, but not as much as an uninsured crash.
Today, I installed a new 25.4mm handlebar and will be tossing the 26.0mm bar as I am not confident of its integrity anymore. Costly mistake, but not as much as an uninsured crash.
02-08-08, 09:45 PM
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02-09-08, 01:54 PM
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At the position it was installed, the face plate and bar had the same curvature, but when I slid the face plate around the bar 90-degrees, there was a huge gap between them. Essentially, the stem ovalized the bar by pinching it at the edges of the stem and face plate.
1. Cheap bars are easy to damage.
B. You over-tightened the clamp.
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This is Africa, 1943. War spits out its violence overhead and the sandy graveyard swallows it up. Her name is King Nine, B-25, medium bomber, Twelfth Air Force. On a hot, still morning she took off from Tunisia to bomb the southern tip of Italy. An errant piece of flak tore a hole in a wing tank and, like a wounded bird, this is where she landed, not to return on this day, or any other day.
This is Africa, 1943. War spits out its violence overhead and the sandy graveyard swallows it up. Her name is King Nine, B-25, medium bomber, Twelfth Air Force. On a hot, still morning she took off from Tunisia to bomb the southern tip of Italy. An errant piece of flak tore a hole in a wing tank and, like a wounded bird, this is where she landed, not to return on this day, or any other day.
02-09-08, 03:52 PM
#18
Senior Member
Actually, I think it's the other way around. Using shims, you can add exactly the amount of material you want in all the places you want it (of course, you need to know how much shim material to add but this is a pretty easy calculation). Even, consistent metal removal using a file, on the other hand, is quite difficult.
02-09-08, 05:09 PM
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02-09-08, 05:12 PM
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+1! The old contact surface holds the right size bar with pretty even pressure 360 degrees around the bar, with a bore that is perpendicular to the steering axis. How to you achieve those qualities in a new surface that you file?
02-09-08, 05:42 PM
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02-09-08, 08:38 PM
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You can use a sheet of low-grit sand paper and move it around the stem hole with a finger. You need to file only 0.3mm.
02-10-08, 09:22 PM
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02-11-08, 02:16 PM
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Ritchey makes them.