Back in the early 80s I rode my Bertin C37bis off road in the woods a lot. I set it up with 46-38T chainrings and a 13-26 FW.
I used Continental Cyclocross sewups - they were marked 27" x 1 1/8"... I still have one on a wheel and it holds air.
In 1992 I built this off road/trekking/gravel grinder frame for rough stuff riding. Lugged butted Reynolds 531 tubing, 700c wheels and so on. It was set up to use with upright or drop bars and clinchers or cyclocross sewups.
Original setup with TA cranks
Updated with Shimano Deore XT triple cranks
I had CX sewups on it at one time. Also 700x47c knobbys but I've been running Specialized Nimbus 700x41c tires on this for years.
verktyg
Chas.