That sort of leads to another question. When looking at tires for a Rad Rover I searched 26X4 on Amazon. One of the choices was a Kenda 26X4.5. Now I don't know if that would work on the rim or not but it's a 1/2" wider than the stock tire. In first gear my chain is about 1/4" from the stock tire and I'm thinking that with a tire that's 1/2" wider then the chain would rub against the tire in first gear which wouldn't be a good thing.