Steve,
The Front Dunlop 4.50L-13 has a diameter of 21" and a circumference of
66.5"
The Rear Dunlop 5.50L-13 has a diameter of 23" and a circumference of
72.5"
I assume that these Dunlops are generally the same as the original
tires made back in the 60s and share these dimensions with them. In
HMSA and General Racing we were required to run the L series but are
now allowed to run the Dunlop M series tires which are a little
smaller in diameter plus being much wider and are more like the Avons
but not quite as sticky. All these tires fit on the same 13" wobbly
rims. Also, some people run a 5.50-13 Goodyear that has about a 25"
diameter and will not fit on the front or back of my car without
hitting the bodywork.
Don Stark
