Home WORLD 1939 BMW R12 750cc Two Cylinder

1939 BMW R12 750cc Two Cylinder


This bike in the heavy weight class bears its old paint with honorable signs of use of the last decades. The huge and reliable engine with SUM carburetor produces with its 745cc enough torque at each rotation speed.

source.image: classic-motorcycle.com

Following the collapse of its aero engine business after WWI, BMW turned to other areas of manufacture, motorcycles among them. BMW’s first model, a two-stroke ultra-lightweight marketed as the Flink, was a failure but its next venture was more successful. BMW’s General Director Franz Josef Popp had asked designer Martin Stolle to come up with a proprietary power unit and the result was the M2B15, a engine that would be supplied to other manufacturers, such as Victoria, as well as being used to power the BMW-made Helios.

Launched at the Paris Show in 1923, and the first motorcycle to be sold as a BMW, the R32 featured a 494cc, twin-cylinder, sidevalve engine having horizontally opposed cylinders, and this ‘flat twin’ layout would forever be associated with the marque. Setting a pattern that endures to this day, BMW’s first motorcycle was relatively expensive but superbly engineered and constructed, while the quality of finish was of the highest order.


It was an immediate success. In 1930 BMW broke fresh ground with the launch of the pressed-steel-framed R11, and followed that up in 1935 with the introduction of a hydraulically-damped telescopic front fork on the R12, the first time such a device had been seen on a mass-produced motorcycle. Also notable as the first BMW motorcycle to have a four-speed gearbox, the R12 was a huge success with approximately 36.000 produced up to 1938, and was used by the Wehrmacht in the war’s early years before the introduction of the purpose-built military R75.

  • Year: 1939
  • Displacement: 745 cc
  • Cylinder: 2 – transverse
  • Bore / Stroke: 78 x 78 mm
  • Power: 18hp @ 3.400 rpm
  • Compression Ratio: 1 : 5.2
  • Weight: 185 kg
  • Top Speed: 110 km/h
  • Production years: 1935 – 1942
  • Units: 36.008