Bmw R11 Series 2-SudetenlandThe motorcycle that U.S. military attaché Nathaniel Bulloch uses to swiftly get around to observe different hot spots during the Sudeten Crisis is a 1931 Series 2 BMW R11. The R11 had an extremely strong twin loop pressed steel frame that could handle extra weight and stress. The M56 four-stroke, two-cylinder, flat twin, 745 cc engine was rated at 18 hp at 3,400 rpm. Top speed was 62 mph, with mileage around 55 mpg.