i ride on 23s with no problem on rough roads--by which i mean, not the most well-maintained roads in connecticut. it's a little uncomfortable--you kind of have to roll your body on the bike over some bumps and shiznit--but it's okay. i wouldn't mind running 25s though.

any thinner than 23mm, you're *not* getting any faster, but you *are* getting a harsher ride.

i liked nashbar's generic kevlar belted tire. it was cheap and solid. but i shredded through it on my rear wheel in about four months. toward the end it gave me lots of flats. i'm using a schwalbe (?) blizzard tire on the back there. it's got a little kevlar belt on it, too, which is nice, i got a good deal on it, and it's nice and grippy and fast, it feels.