Joined: Dec 2004
Posts: 12,538
Likes: 791
From: Middle of da Mitten
Bikes: Trek 7500, RANS V-Rex, Optima Baron, Velokraft NoCom, M-5 Carbon Highracer, Catrike Speed
Back 40+ years ago when I had a bike with 27" tires, I found that 27x1 1/4 was OK (barely) for most gravel, but 27x1 1/8 was dicey. My hybrid ran 700x35 knobbies for a while, and that was pretty good on most gravel.