Originally Posted by
Seattle Forrest
I've been using 28s and thinking I'd go to 32 mm for my next tires (pretty soon). Deep gravel, fields of bigger rocks, and sand are my enemies, but 28 has been good for all the dirt I've thrown at it.
I don't know how wide you can go and still be fast on pavement. I'm doing about 2/3 of my miles on paved roads and the other 1/3 on dirt roads. Haven't found the ideal compromise yet but I'm going to try 32 mm next
My experience with combined bike/rider weight of 190-200lb has been this:
28mm (measured width) are fast on pavement and really smooth gravel. They really slow down when road conditions deteriorate.
30mm are just as fast, but can handle drier and wetter conditions on maintained dirt roads
32mm is the tipping point for me where tire inertia (with 450g tires) is noticeable on fast group road rides. Lighter 32mm tires, like Compass/Grand Bois or GP4000 on a really wide rim, would not be a handicap on fast group road rides. 32mm is also the starting size for fast gravel riding that can survive most conditions. Most of my riding is on pavement with 31-33mm tires, and I feel confident taking sandy or gravelly or rooty shortcuts with those tires.
35mm or more are reserved for rides that are >60% gravel or have some gnarly unmaintained roads. They still roll fast on pavement, but the air resistance and moment of inertia are apparent.