VCCA Home Forums Thread Like Summary - 27 Chevrolet tires

Where can you get tires?

Before the mid-1930s, tire sizes related to the outside diameter of the tire, not the inside diameter, which equates to rim size.

So, your old tire of 29/440 means that the outside diameter (29 inches) minus the total height of the tire (4.40 inches times 2 (across the diameter of the wheel it takes two heights of the tire)) makes a rims size of 20 (29-8.8=20).

;-) Dean