On most tours I have two sets of tires. For the road my current picks are a Conti 4-Seasons 28f & 32r and for dirt Conti AT Ride or Speed Ride 40mm f&r. But those tires assume I am going to spend most of a given day either on sealed surface or dirt.

On a ride down the Pacific NW coast, switching from paved to dirt roads sometimes four or five times during the day the idea of switching tires out every hour or two was a non-starter. (A really fun ride by the way.) For that ride I had Schawlbe Duremes 35f and 40r. The Dureme was a heavy, deep treaded multi purpose tire. They worked well but were a compromise. My wife talked me into riding the Portland, Or Century Ride a few days before I started the above tour. It took me and hour longer than the previous years time for the exact same course using the Duremes. I’ve never mounted those tires again but given the right route they might be the right tires.

Here’s maybe an arcane observation. I’ve found that slick and semi slick road tires much wider than 32mm don’t track all that well on pavement and on dirt, even in the best of conditions, are pretty tentative. For someone with a 60+ lb load in four panniers this might not be an issue, but I try and keep it down to around 25 lb and love letting lose on long, winding downhill descents while having the rear wheel track the front on tight curves.