Just one thing before you buy. The big difference between the Speedmaster and America is the seating position. Sit or, better, test ride on both and choose the one you both find most comfortable. The difference in performance between a Sportster and a Triumph twin is surprisingly little with the Triumph winning easily in handling. Another huge difference is that Triumph uses balance shafts in the engine instead of rubber mounts to dampen vibration. After 4 years with my America, the only Harley I can stand to ride is the later Softail with the B engine.
