BMW R 66

The BMW R 66 was a BMW motorcycle built from 1938 to 1941 with a two-cylinder boxer four-stroke engine and shaft drive. It was the sporting model and the sister of the side-valve touring R 61. BMW presented it on 18 February 1938 at the Berlin motor show with the R 51, R 61 and R 71, four engine variants from 500 to 750 cc in a single chassis with rear suspension. Its engine, the M 266/1, was a longitudinally mounted boxer with overhead valves, the four-speed gearbox was foot shifted, and the entire drive train was enclosed against dirt and moisture, in contrast to the open chain drives that were still usual at the time.