What is the actual outside width of the demountable rims? I have some that are 2 1/2 and some that are 3 inches. My thought was that the 2 1/2 inch were for 30X3 and the and the 3 inch were for the 30X3 1/2.
How about this?
And if it's 31/8" it's C#‹*®ø¬ªt.
Thats funny I would have thought the rim diameter would be the same on both rims seeing that they are both 30 in tires.
Richard the (nominal) outside diameter of the tires is 30". The 30x3-1/2" tires are taller in cross section in addition to being wider, so their rims are smaller diameter than the 30x3" ones.
Thanks for the information. Just type a question on this forum and you get a answer before you get up from the computer.
Richard: As Mike stated the 30 inch is the outside diameter of the tire. To calculate the rim diameter there is a formula. For 30 X 3-1/2 inch you take the 3-1/2 inch tire (side wall height) and double it. that will give you 7 inches of sidewall height. Then subtract the 7 inches from the 30 inch tire diameter to give you a 23 inch rim size. 30 - 7 (3-1/2 + 3-1/2)= 23 inch rim. Do the same thing for a 30 X 3 inch tire. double the 3 inch to get 6 inches. Then subtract the 6 inches from the 30 inch tire diameter to arrive at a 24 inch rim. 30 - 6 (3 + 3) = 24 inch rim ... The 3 inch and 3-1/2 inch size is the profile of the tire and not the width. At least that is what I was always taught ...