Originally Posted by
cycle_maven
That being said, 27" (630) tires are widely available, but there might not be as great a selection as for 700c tires, especially in the narrower widths.
Too true. Since you can still buy decent wheels in the 27" size, as well as a variety of different tires, there's not much of a reason to switch to 700c unless you need really high performance wheels/tires. As far as trying to put 700c tires on a 27" rim, I can't say that I've ever tried it, but I can definitely say that I wouldn't want to...especially since my LBS carries a great selection of 27" tires.