Home Technology Vintage BMW R51/2 1950 500cc 2 Cylinder Motorcycle Starting Up

Vintage BMW R51/2 1950 500cc 2 Cylinder Motorcycle Starting Up


BMW introduced its first post-war twin-cylinder model in 1949. This was the R51/2 based, as its designation suggests, on the pre-war R51.

source/image(PrtSc): classic-motorcycle.com

Introduced in 1938, the latter was an updated version of the R5 of 1936, which had represented a new departure for BMW by virtue of its method of valve actuation, adopting two chain-driven camshafts that permitted shorter pushrods and higher revs.

The R51 deployed the R5-type engine in new cycle parts that featured a telescopic front fork and plunger rear suspension, while improvements incorporated into the post-war R51/2 included a two-way damped front fork, a gearbox main-shaft damper and a strengthened frame.


According to the records of the BMW Archive: This bike has been manufactured on Dec.11th, 1950 and delivered on Feb. 14th, 1951 to the BMW dealer Schorsch Meier in Munich, Germany. This BMW has been restored 10 years ago. Its in great shape and its fitted with an electronic ignition from the well-known company “Powerdynamo”.//classic-motorcycle.com

  • Manufacturer: BMW
  • Model: R51/2
  • Year: 1950
  • Displacement: 494 cc
  • Cylinder: 2 – transverse
  • Engine type: 4-stroke / ohv
  • Bore / Stroke: 68 x 68 mm
  • Power: 24hp @ 5800 rpm
  • Compression Ratio: 1:6.3
  • Weight: 185 kg
  • Top Speed: 140 km/h
  • Production years: 1950-1951
  • Units: 5000