26mm quill stem clamp not holding a 26mm bar
 

I had to replace the original quill stem on my 1999 bike which has a 1" headset but kept the handlebars. I found a beautiful vintage 26mm Cinelli 1A stem on Ebay that I purchased. The original handlebars are ITM Super Italia Pro-260 which are 26mm in diameter where the stem clamps. The problem is that there is play in the handlebars even when I get the clamp as tight as I dare to go. One of the suggestions I saw was to cut a shim out of a beer can and place it between the clamp and handlebar. That still doesn't provide enough bite for the clamp. Am I missing something or does anyone have any suggestions?

Have you checked the bar width with a set of precision calipers?

Obviously, one of the two items are not 26.0, but it is hard to measure the stem as easily.

Cinelli used a 26.4mm standard for quite a while back in the vintage days. The 1a was produced in both 26 & 26.4. Don't recall when they changed. Do a search.

Unfortunately, sellers on Ebay often just say 26 when it could be the old standard.

Thanks for the info, I bet that's it.

Have you tried a handle bar shim in place of the "beer can" shim, it looks a lot better that a cut up beer can.

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...if it is that, you can still find 26.4 bars, but only used, I think. I don't know if anyone is still making them new.

If you need to sleeve a 26.0 bar to a 26.4mm stem, you will need a 0.2mm shim which is approximately 0.008"; IIRC a beer/soda can is about 0.003" to 0.005" on the sides. Many hardware and big box stores have a K&S Metals display which likely has the correct shim stock. If not, a local machine shop (you only need a small piece) or McMaster-Carr should be able to help.

I have yet to see any new 26.4 bars out there I would doubt anyone would make them unless custom. It never caught on as a standard and didn't stick around for a long enough time to really grab people. Everyone wants to try to change the standards and make something better and sometimes it works and a lot of times it makes it worse or fades away.

I do like Cinelli as a company and like many of their components and frames and such. My new 1A is fantastic and looks great. I just need to figure out if I am dumb and want to get it pantographed with the Phil logo for my Phil Wood bike or if I should leave well enough alone it looks great and save that money for something else.

Nitto, Problem Solvers, and probably others offer actual handlebar shims. Machine shops could probably cut a piece of appropriate shim stock to do the same thing.

The great thing about standards is that there are so many of them. :)

Thanks for the replies; I think I'll try a proper shim. The ones I've seen so far are for 25.4mm -> 26mm but I bet those will probably work.

They come as a set of 2 pieces, you might be able to just use one for your issue.

...and once you match the handlebars with the stem, a little smear of toothpaste on the mating surfaces will help hold the bar position

How about some carbon fiber paste?

never tried it. Is it gritty?

Yeah, moreso than toothpaste. Just not sure if a dry interface would be better or not.

Just closing the loop on this one. I tried cutting out a piece of aluminum from a piece of downspout I had around the garage. It fit tightly between the handlebar and stem but it must have been too smooth because I could, with a little effort, rotate the handlebars in the clamp. I ended up ordering a 24.4mm -> 26mm shim from Velo Orange and I put it in today. Works like a champ. The surface of the shim is micro textured so it provides some grip in the clamp. After installing the shifters, running the cables, and wrapping the bars I should be good to go.

I have a problem with handlebars rotating, but rather than those lovely aluminium clamps I have those (un)lovely pressed steel clamps where the nut and bolt are never going to seat on flat let alone parallel surfaces. I seek a replacement, I have even considered using a quill stem with my quill-less stem clamp if I could find one of the right size.