AndrewP, thanks. I've alreadey read that article and looked over that chart, which is the reason for my question. Sheldon warns about putting a narrow tire on a wide rim, and I was wondering whether 26x2.00 tires would be too narrow. Seems like they wouldn't be, but I just don't know. Are you sure I'd be better with 26x1.5 tires on 26x2.125 rims; 26x1.5 tires would seem be a little too narrow to me. The inner rim width of my rims, measured very inexactly with s metal tape measure, is approximately 28 mm.