Tire Sizes and Options... What do the Numbers Mean ??

[BearsFan315]

OK, In looking for tires for my 1930 Chevrolet AD Universal - Canopy Express Truck (Huckster) per the Manual the Tire size is 19" x 4.75". What excatly does this mean ?? I know that 19" is the Rim Diameter, but the 4.75" is that the tread width or Cross Section of the tire ??

I looked at the size on the tires that are currently on there, and they say this tire replaces 19"x 4.25", 4.75", 5.00", & 5.25". I measured the tires, the Approx Outside Diameter (Overall) is about 30.00" and the tread width is Approx 3.88" with the Cross section or Bulge Diameter Approx 4.50".

My question is wha tsize tires should I be looking for ??

When shopping around (COker for Example) I see sizes like 19x400, 19x450, etc... what sizes can I Use ?? can i use a larger cross section and tread width ?? Pros Cons, Thoughts ??

[stakeside]

OK, In looking for tires for my 1930 Chevrolet AD Universal - Canopy Express Truck (Huckster) per the Manual the Tire size is 19" x 4.75". What excatly does this mean ?? I know that 19" is the Rim Diameter, but the 4.75" is that the tread width or Cross Section of the tire ??

I looked at the size on the tires that are currently on there, and they say this tire replaces 19"x 4.25", 4.75", 5.00", & 5.25". I measured the tires, the Approx Outside Diameter (Overall) is about 30.00" and the tread width is Approx 3.88" with the Cross section or Bulge Diameter Approx 4.50".

My question is wha tsize tires should I be looking for ??

When shopping around (COker for Example) I see sizes like 19x400, 19x450, etc... what sizes can I Use ?? can i use a larger cross section and tread width ?? Pros Cons, Thoughts ??

Try Universal or Lucas tire. I believe they have refference material that can give you the correct tire.

I was able to get 5.25x21 6ply tires for my 29 Dodge Bros. Be sure and get the rubber rim liners to protect the tubes

[bhclark]

The 4.75" refers to the actual height of the tire. So, a 19x4.75 would be a total of 28.5 inches tall.

[Rusty_OToole]

OK, In looking for tires for my 1930 Chevrolet AD Universal - Canopy Express Truck (Huckster) per the Manual the Tire size is 19" x 4.75". What excatly does this mean ?? I know that 19" is the Rim Diameter, but the 4.75" is that the tread width or Cross Section of the tire ??

I looked at the size on the tires that are currently on there, and they say this tire replaces 19"x 4.25", 4.75", 5.00", & 5.25". I measured the tires, the Approx Outside Diameter (Overall) is about 30.00" and the tread width is Approx 3.88" with the Cross section or Bulge Diameter Approx 4.50".

My question is wha tsize tires should I be looking for ??

When shopping around (COker for Example) I see sizes like 19x400, 19x450, etc... what sizes can I Use ?? can i use a larger cross section and tread width ?? Pros Cons, Thoughts ??

19" is the inside diameter of the wheel in other words measured where the bead seats on the rim, not the outside measurement. The 4.75" is the height of the tire and it is also the width of the tire. In those days all tires were as wide as the are high, this is called the aspect ratio. A tire that is round in cross section has an aspect ratio of 100, if it is 75% as high as it is wide it has an aspect ratio of 75 etc.

[BearsFan315]

Thanks for all the input...

Just tryingto LEARN how they sized the tires in those days so i can get my 1930 some new shoes in resto. I am very keen on the modern tire sizing methology and the numbering, just lsot on the old world schema !!