Originally Posted by
chaadster
Hmm, is that true? It doesn't seem like it would be, at least not in a meaningful way. I mean, I might expect carbon rims to have a bit more external width than aluminum, but that doesn't affect tire casing size. I also don't think there would be any shortage of alu rims at any desired width, but I'm not sure if you're talking rims, or wheelsets, or limiting the terms to $600 or what. It just strikes me as a strange thing to say in any case, and I really wonder if it is true.
Width was ref to rim for 700C hooked clincher road wheels (not MTB).
That is my observation, alloy's are narrower. In tubulars I see some carbon 20.5mm (I have some), but I am not aware of any in clincher that are carbon and <23mm wide. I would exclude carbons with alloy brake track from that narrow comment. An eBay search on "25mm width clincher", "25mm width alloy clincher" might help. There are many <23mm alloy clinchers or carbon with alloy track.
The width at the brake track has some affect on my tire choice. I want the tire to match / look as well as protect the rim. Same with car tires where the rim will be the first to kit the curb.