Now that my old touring bike has died, I'm looking around for a new bike. Probably the single most important selection criteria that I have is the ability for the bike to accept fat tires. The largest tire my old bike could accommodate was 35mm, I found that to be way too narrow for some gravel roads, it was just too hard on the body. The comfort afforded by larger tires cannot be overstated after spending days or even a few hours riding gravel, so my advice - go large.
