18" tyres

[Lynn Eades]

David, I am sure others know more than I, but as you have probably noticed, the majority of wartime 900 x 16 tyres had on them "for British wheels only" or "for 6"rims only" or " for American wheels only"
One wheel has a "flat" base, and the other, a "tapered" base.
Obviously the two allies couldn't agree on a common standard (like they did with the inch)
I had a Dodge 6x6 at one stage, and from the process of measuring up rolling circumferances of the 20 plus various 900 x 16s, I found few to be the same. As an example, the standard British Dunlop track grips were quite a bit smaller than the same make run flats. (The runflats were post war and should have been on a Ferret)
I also had British Avon, Michelin, Blackhawk chiefs, Yokohama (1960-70s)along with a mix of Goodyears, and other names forgotten, including sand tyres made in the Federal Republik of Suid Afrika. Obviously some were worn more than others, but as I recall the circumference varied a max of about 8 1/2". A lot in for 1 turn of the wheel!