1945–1955

In Soviet-controlled East Germany, BMW's sole motorcycle plant in Eisenach recommenced production of R35 and R75 motorcycles soon after the war, for reparations. The factory continued to use the BMW name, causing two separate companies (one in Eisenach and the other in Munich, West Germany) to be using the BMW name between 1948 and 1952. The head office of BMW, based in Munich, had no control over the operations in East Germany. Eventually in 1952, after the Soviets ceded control of the plant to the East German Government, and following a trademark lawsuit, the East German company was renamed Eisenacher Motorenwerk (EMW). Instead of BMW's blue-and-white roundel, EMW used a very similar red-and-white roundel as its logo.

In West Germany, many of BMWs facilities had been badly damaged during the war, including the Munich factory which was in ruins. Initially, the terms of Germany's surrender forbade BMW from manufacturing motorcycles. In 1947, when BMW received permission to restart motorcycle production from US authorities in Bavaria, BMW had to start from scratch. There were no plans, blueprints, or schematic drawings because they were all in Eisenach. The first post-war BMW motorcycle in Western Germany, was the 1948 BMW R 24. The R 24 was reverse-engineered from the pre-war BMW R 23 motorcycle with several improvements and powered by a 247 cc (15 cu in) single-cylinder engine. It was the only postwar West German model without rear suspension. In 1949, BMW produced 9,200 units and by 1950 production surpassed 17,000 units.

Production of flat-twin models resumed in 1950 with the 500 cc (31 cu in) R 51/2 model, which was followed by the BMW R 51/3 and BMW R 67 twins in 1951, and the sporting 26 kW (35 hp) BMW R 68 in 1952. Except for the R 68, all flat-twin models came with "bell-bottom" front fenders and front stands.