I was wanted to give riser (or flat) bars a try, just to check them out, but it seems that the clamp size for pretty much all riser bars is 25.4 or 31.8 (the mountain standard). Does anyone know of a riser bar I could buy/order that would fit my current stem's clamp diameter of 26.0?

I know I could just get a mountain stem for my fork (I have a Surly Steamroller threadless fork, 1 1/8), but I'd rather not buy a new stem AND bars, in case I hate riding with risers.