I just thought I'd report that I installed the Kool Stop Mountains on my bike. They fit my 20" rims just about perfectly, though there isn't much room for error. The curve look like it was designed for 20" wheels. One annoyance though is the plow tip thing that sticks out a bit at the rear of the pad. It's supposed to squeegee water in the rain, but on my v-brakes, even with the brake pull a bit longer than I'd like, they rub against the rim, so the wheel doesn't spin quite freely. I don't feel it while I'm riding though, so it's probably a minor thing. I could shave them down, I suppose, but I haven't bothered yet. Maybe they'll wear off.