I currently have 27 x 1 1/8 wheels. The rims measure to be approx 25 1/4" (641mm). In a perfect world, I'd swap them for rims that measure more like 650mm to give a bit more to the short reach calipers that I've already installed. If I understand the standards correctly, rims for current 700c wheels measure in at 622mm.
So...the question: Are there modern rims that measure in at 650mm?