Ron_S from Overland Park on 8/12/2021 12:50:05 PM:
The questions of tire width often appears here. What should go along with that is “tire pressure.” Current theory is to use softer tires/lower pressure as the surface gets rougher. The softer tire rolls over the rough gravel, bumps, etc while the hard inflated tire is slowed a bit on these surfaces and gives a harsher, more fatiguing ride. There is a good tire pressure page on the Silca site. (Silca.cc) The “Pro” version gives the most complete result. As an example, the bike I usually use on the trails has 38mm wide tires (Compass Barlow Pass). On standard paved surfaces the recommended inflation for the total weight of me, the bike, and the load (260#, full camping gear included) is 50 PSI. On the trail, which in the Silca chart would be category 3 gravel, the recommendation is 38 PSI. Note: Some tires have stiffer sidewalls than others and the effect may not be as pronounced. Play with it and see what works for you. i.e., my Schwalbe Marathons have a sidewall so stiff they would probably hold up even without air. My Compass Barlow Pass supple sidewall tires are like riding on Jell-O at low pressures. But they are definitely faster and more comfortable. YMMV.