Glad to see this topic appear. I have been fruitlessly preaching this idea for decades since I bought my Bruce Gordon RNR. You get the best of both a touring bike and a mountain bike. The maximum tire size is 700x47 with fenders. (I could fit the 50mm but would have to lose the fenders.) I am still using some Schwalbe Marathon XR tires from my hoarded stash. I have not had to use some of their newer designs as yet.

This volume has worked well in all conditions on and off pavement except for extreme sand and mud. Schwalbe Marathon XR's tread rolls very well on pavement and at low pressures allowed me to ride the Divide Ride on the rigid RNR much to the surprise of other tourists and even the staff at ACA in Missoula. They thought that I had the wrong wheel and tire size for the Divide Ride.