ottoluck,
I was hoping someone that knows Cockshutt's better than I do would answer your question, but I guess not. So I will try. First, in the late 50's the tire companys put new tire markings on their tires. there was nothing changed between the old tires and the new tires. I will give you six examples:
New number 11.2x38 is exactly the same as the old 10x38.
New number 12.4x38 is exactly the same as the old 11x38.
New number 13.6x38 is exactly the same as the old 12x38.
New number 14.9x38 is exactly the same as the old 13x38. New number 16.9x34 is exactly the same as the old 14x34.
New number 18.4x34 is exactly the same as the old 15x34. I have several old advertising brochures, and I will list the standard size as well as the optional size for the 30-40-& 50 tractors. I will also use the old numbering system. The 30 (E3) tractors had 11x38 as standard and 12x38's as an option. One early brochure states 10x38 as standard and 11x38 as an option.
The 40 (E4) tractors had 12x38 as standard and 13x38's as an option.
The 50 (E5) tractors had 14x34 as standard and 15x34's as an option. As to what rim width was used on the three tractors, I will make a guess.
The 30 most likely had 11 inch rims.
The 40 most likely had 12 inch rims.
The 50 most likely had 13 or 14 inch rims. NOW REMEMBER THIS IS ONLY A GUESS ON MY PART. The tractor companys did not start using wider rims until about 1958 or 1959. Maybe someone will correct the above information if I am wrong.
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