The Speedmasters run (ran?) the 110/80B18's, and the America's run the 110/90B18's. But the America tire will clear and fit under the Speedmasters "shorty" front fender.
I think the lower profile "80" series tire better suites the Speedmaster's intended purpose, while the taller "90" series tire better suites the America's more laid back, cruising style. If the Speedy came with an "90" series tire, I would have to think the dealer had done some wheel swappin' or somehow mixed them up. Was it on a stock Speedmaster wheel?
