BMWR51/2 1950 - 1951

　　In 1950, BMW started to manufacture the R51/2, a motorcycle based on the R51 model, which had taken the chassis and basic engine design from its predecessor. In late 1949, at the Munich plant, the BMW R51/2 was presented for the first time to the press, and in 1950 BMW released the first post-war boxer engine.

　　There were no big differences between the R51/2 and R51 except for the slip valve covers that were held together with a clip. BMW demonstrated that they were in tune with the times, and in one year of production 5,000 units were manufactured. After one year of production, the R51/2 was replaced by the R51/3.

　　The 1950 R51/2 was also favored by the government agencies such as the police which opted for the heavy BMW machines again. President Heuss’s federal escort received six of the first copies manufactured at the time.

　　The model featured a 494cc air-cooled four-stroke twin-cylinder boxer engine that delivered an output power of 24 hp at 5,800 rpm and was fitted with a four-speed manual transmission. The bike had a weight of 185 kg (407 lbs) and a top speed of 135 kph (83 mph).

　　The front telescopic fork featured a hydraulic damper, and the rear had a telescopic suspension. The model came with wired-spoked wheels and 200 mm brake drum units front and rear, and a twin cigar-shaped exhaust.