sjpitts 

I have discovered that the Cinelli Stem I got for my wife's bike is 26.4. However, the bars I plan to put on the bike are 26.0 bars.

Now Nitto makes a shim for shimming for 25.4 bars into 26.0 stems.

https://www.rivbike.com/product-p/hb91.htm

But this is not quite the same as shimming 26.0 bars into 26.4 stems.

Has anyone ever tried this and had it work?

I did some searching, and I saw where several people asked the question, but I didn't see a "yes this will work" or "no it will not"

I saw someone suggest using a beer can shim. Seems kind of risky

I saw someone suggesting using only one side of the nitto shim. Seems more promising.

Obviously the difference between 25.4 and 26.0 is .6, but the difference between 26.0 and 26.4 is only .4. But is that close enough to make it not work?

Jared

PS: If anyone is interested in a trade, this stem is a cinelli 85mm 26.4. It is in good condition. I would like an 85 or 90mm in a 26.0. A 3ttt would probably be preferred. I also have a couple longer 26.0 stems I could trade. And a couple nice nitto 25.4 stems. I would also be interested in a 40-42 cm cinelli 26.4 bar. But not one with a real deep drop.

mkeller234

Here is a question for you: Even if someone says "yes, it's ok", will your mind ever be 100% at ease? Will you always look at that bike and think, "I hope that is ok"?

clubman 

In a perfect world, the shim would be of a thickness that would allow it to wrap all the way around the bar, leaving a small end gap at the split near the binder bolt. The final diameter would have to be 26.4 plus or minus some very small amount. This way there wouldn't be a stress riser to cause the stem to fail. Try it. If the shim is too thick there is thinner shim stock available, usually in brass.

ColonelJLloyd 

All the responses in the world are no substitute for trying it. Try your bars with the shims and see if you're able to insert them. Likely, you won't be able to. Then, try only half of the shim (it's two pieces) and go from there. I've used only half of the shim without issue with a 25.4 bar that wouldn't go into a 26.0 clamp stem. It's going to feel great in the stand and with 99% of your riding. The test is the pothole or small curb like that at the end of a concrete driveway. If you're not comfortable with this, don't do it. But, since you're asking I assume you aren't entirely risk averse.

Use a wooden wedge or other technique to keep your stem clamp open and avoid scratching your bar.

due ruote 

+1 I'd rather use thinnner shim stock, even a soda can, than only half a Nitto shim.

I have shimmed numerous bars with alum. can shims and see no problem doing so. It isn't as though it's going to fall out.

buldogge

Shim stock is sold in all kinds of thicknesses...available at any decent hardware store or hobby shop...I like to use brass.

If you don't care about pristine, I have some 64-40s or 42s (have to look) I could let go.

busdriver1959

What's the worst that can happen? You hit a bump and your bars move a little bit. You won't die. I have a beer can shim on a set of 26.0 bullhorns in a 26.4 stem. They don't move when I hit bumps and I'm still alive.

Grim

I might be interested in a trade.
I'm looking for a Cinelli stem to replace the 130 mm I have thats too long for me unfortunately I think I want 100mm. Let me see if I can mock up the shorter length
Let me dig around and see what I have. I had a shorter Nitto at one time but I dont know what I have done with it.
Post a picture of the stem you have if you would.

sjpitts 

To those who are interested in a stem trade, here are pictures of the cinelli stem. As I said, it is an 85mm stem with a 26.4 clamp. I need an 85-90mm in a 26.0

Jared

BentLink

I used some Aluminum shim stock (can't recall the thickness, and too lazy to do the math again) that worked fine...approaching 1,000 mi with no problem.