I picked up a new shorter stem online to try on my Seven steel roadie as after a year in the saddle with this bike and my ability has increased I'm realizing it's a tad big for me, a 58 with my two other roadies being 56s. I'm going from 110mm to 90mm. When I went to put it on I discovered the new stem is sized for a 31.8 bar and apparently I've got a 25.4. Looking online I see very few offerings in the smaller size so my first question is is there a shim that can be used to make this stem work? The second question is, the Seven has a "seven wound up" fork, the bike being from 2004 which I picked up used, how do I tell if it has a carbon steering tube? It was black and looked like carbon but this is all new to me. I ask as most of the inexpensive 25.4 stems said not to be used on carbon steerers. A third question comes up, should I be using a torque wrench when tightening the stem to the steerer? I'll be heading down to my LBS later but thought I'd try here first.
Thanks in advance

First, you likely have 26.0 handlebars. That was the road bike standard. 25.4 is a mountain bike standard.

Second you can shim a 31.8mm stem to a 26.0 bar. Problemsolvers amongst other make them.

Third, you can still find stems with 26.0 openings. If you're buying new, that would be the A answer.

Fourth, If you have to ask if you need a torque wrench, you need a torque wrench.

Fifth, it should be pretty obvious if the steerer tube is carbon. Look at the finish on the inside of the tube. My bet is a woundup fork of that era came with an aluminum steerer tube. You could also google wound up.

Yes, there are shims and they work well. Sure, some folks are dubious about them, but properly installed they are no problem at all.

Look down from the top at your steerer. If it is solid black from inside to outside, it is probably carbon. You should be able to see some texture on the surface denoting the carbon fabric. I don't know what wound up is, but it may be carbon over aluminum. You might be able to see that too as a silver look on the insider diameter and black on the outside. Calling Seven couldn't hurt.

Absolutely use a torque wrench to tighten the stem to the steerer especially if your steerer is carbon. Most stems say 6 Nm max, but I use a little less. Also check whether your fork maker has any specs.

Robert

Also, have you considered new handlebars? Aluminum handlebars can and do corrode. At 10 years old, if the bike been used alot, ridden in bad weather, in a coastal environment, or used on a trainer, the bars could be corroded and in need of replacement. You should at least rewarap the bartape and inspect them.

That was easy.

Thanks for the quick responses. I googled wound up as suggested, great idea. I have a carbon steerer with aluminum sleeve so it uses a star fangled nut. Will pick up a torque wrench but need to research what I need as a home bike techie. I've thought about new bars similar to the compact bars I have on my Spesh Sectuer, good idea.

In case you're interested in the simpler solution...

https://www.amazon.com/Dimension-Thre.../dp/B005Z5B2MK

Torque wrench for stems and bars is a low torque model. 10 Nm is more than enough range. For BB, cranks, and cassette tightening you need a higher range in the area of 40 Nm.

Kids these days with their star fangled nuts.

Thanks Phil,
That looks tempting and I found the same one in 26.0 which merlin corrected me on, but dimension doesn't recommend them for carbon steerers. It looks like I have a carbon steerer with an aluminum sleeve. I don't know yet whether the aluminum sleeve makes any difference in terms of which stems can be used. Learned a lot already today, thanks all.

No, the steerer doesn't matter. Either carbon or aluminum stems work.

Robert

I don't think I was clear enough Robert, the Dimension aluminum stem in question said not for use with carbon steerers. And thanks for the info on what to look for in a torque wrench, not planning on anything heavier duty than stems and such.

You want a stem with two bolts in the back facing in opposite directions. There are plenty of stems out there. No need to focus on the Dimension. The bar shims really work fine. Don't limit yourself to a 26.0 bar clamp.

Thanks,that was really helpful. The stem that I purchased , an Easton lower level has just that, opposite bolts and no caution about carbon steerers. Will try my LBS tomorrow for a shim

They come in two pieces, each one half of the circle so you don't hav e slide it over the bar from the end. Be sure to center the seam between the two halves on the separation between tbe clamp face and the stem body. You want the two halves of the clamp to squeeze the two halves of the shim together.

Looks like I need a torque wrench. At this point I don't anticipate any major bike repairing/building and thinking something like a Ritchey torq key would suffice for minor stuff like stems and such. Even if I wanted to do more with a better wrench down the road it looks like an easy to use handy tool.Any feedback out there?

An update. I was about to order some shims for 26mm when I thought it prudent to actually measure mine. I had to take off some of my gadgets to find space to get the calipers in. Found they are Cinelli brand and measure 25.4mm. I'll be off to my lbs today to see if they can help out. Still undecided about what direction to go with the torque wrench, the simple Ritchey or similar or something like the $60 kit Nashbar offers.

A final update. I ended up ordering a Problem Solver set of shims, 25.4-31.8 from my LBS who gave me a better price than I could find online. Installed this morning without a hitch and a 2 mile ride in a light rain. Of course I need a long ride to know but my initial impressions are it feels great and more natural to my body. I went from 110 to 90mm.This bike was built as a 58 and my other two roadies are 56s.
Still on the fence about a torque wrench. I asked my LBS mechanic about whether I needed a torque wrench due to the carbon steerer but he said not to worry as the Seven wound up fork with the aluminum sleeve is bomber. He's a Seven dealer as well.
Thanks Robert and Merlin for your great help!

My torque wrenches are big manly things, none of which are useful for delicate bike bits -- so I need one. I've managed fine without one so far, but each time I risk it, I think of the classic way to get by without one: tighten the nut until you break the bolt, then back it off a little.

Glad you solved your problem!

Get a Torque Key or equivalent. Full size torque wrenchs are too big and bulky for most small carbon parts. If you get a Torque Key you will use it reliably. If you get a torque wrench you'll use it twice, put it in a drawer and never bother with it. Make sure the Torque Key has interchangeable bits.

i just did exactly the same as the op. i got a shim for my smaller bars which cost me like £4 and i will see if this 110 to 90mm stem change is enough. if i need to get a compact bar that will be the next step.

unfortunately it has been raining non-stop since the stem was changed and i can't say if 110 to 90 was right. surely 20mm shorter should feel different right?

shims for under a $1.

tin snips + soda can = cheap shims stack or wrap as appropriate.