I'm resurrecting a '66 CM91 that was outdoor stored for 40 yrs. I have posted engine question in another section & progress is being made. Now I'm looking at tires & wheels. Doing this on a budget to begin. If all goes well I might re-visit some restoration items to improve the cosmetics. Cheap tires (approx $20) are 2.50 x 17, 290 pound 74 mph ratings. That matches the bike's oem ratings just barely, but I'm not going to ride this 2-up on the freeway anyhow! I could go with 2.75 x 17 on the rear to gain a bit more capacity for occasional 2-up riding or better traction at about the same price. Will this bike handle 2.75 on the rear??? Then there is the rust question. Rims cleaned up (chrome) pretty well with steel wool. But there is some rust on the inside (spoke ends area) of the rim. How clean must I get this area to be serviceable?? Should I paint this area with rustoleum or what ??? Thanks for your comments.