I've picked up a new (used) road bike but I need to change the stem length and I don't like the handlebars. I have a pair of Bontrager handlebars that I love but the center diameter is 26mm. The handlebars coming off the newer bike have a 31.8 mm center diameter. I can get a stem in the proper length and clamp diameter to accommodate either bar, but I want to know how much I'd be giving up in the way of strength going to the smaller center dia bar. Any other pros/cons to swapping the bars as long as I'm changing stems anyway?

Do your accessories have adapters for different bar diameters (bike computer, headlamp, etc mounts)?

Myosmith, I think using a handle bar that you like would out weigh whatever strength differences there may be.

Brad

The benefits of 31.8 for carbon bars are hard to challenge, but IMO the only real advantage of the bigger diameter for aluminum bars is that they fit the same stem.

Most amateurs and other mortals won't feel any deficiency in 26.0 mm handlebars, in fact they were used by pros until a relatively few years ago.

As for using them with your current stem, just get a set of these adapters, they work well and are pretty much invisible:

My take is that you keep the bars you like with the 26mm clamp and get a stem with 31.8 and use the shims mentioned above. It seems that 26.0 bars and stems are becoming more scarce all the time and you'll have more options of handlebars if you decide to change in the future. Also agree with others that larger clamp size isn't always stronger/stiffer. It's more dependent on the type/thickness of aluminum or CF used although with CF I prefer a larger clamp due to the fact that with a larger clamp area you need less clamping force and less likely to cause damage by over torqueing.