Yesterday's Tractors has published a fascinating report from International Harvester, a Sales Department Bulletin dated May 20, 1936. In this bulletin, IHC gives the various speeds of IHC tractors on steel and on rubber tires (in some cases, of more than one size). There are even reasons given why the company prefers one size over another. For F-20, for example, the company said that the 36" wheels made the tractor tilt down too much at the front! Still, most F-20s in my experience had the 36" wheels because anything smaller would not clear the brake drums and they made the tractor EXTREMELY wide.
The site is www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=752928.
The site is www.ytmag.com/cgi-bin/viewit.cgi?bd=farmall&th=752928.