The BMW R51/3 was BMW's second post-World War II 500 cc motorcycle, following the briefly produced R51/2. It featured a flat-twin engine and exposed drive shaft. In 1951, the R51/3 succeeded and modernized the 1950 R51/2, which was essentially a pre-war design that was produced after the war. The 600 cc R67, R67/2, and R67/3 series and the more sporting R68 model also followed the R51/2.
History Following World War II, Germany was precluded from producing motorcycles of any sort by the Allies. When the ban was lifted, in Allied-controlled Western Germany, BMW had to start from scratch. There were no plans, blueprints, or schematic drawings. Company engineers had to use surviving pre-war motorcycles to create new plans. In 1948, it introduced the 250 cc R24, which was essentially a pre-war R23, complete with rigid rear end.
When larger machines were permitted, BMW introduced its R51/2 in 1950, a model that was in production for only one year and that was essentially a pre-war BMW produced after the war. The R51/3 was then introduced in 1951 for a production run of four years.
The 600 cc R67, sister model to the R51/3 and almost identical visually, was also introduced in 1951, but it went through two revisions. The more powerful R67/2 came out one year later and was replaced in 1955 by the R67/3, which was in production through the 1956 model year.
In 1952, BMW introduced the 600 cc R68, which produced , had a compression ratio of 8.0:1.
Technical data
R51/3R67 – R67/3DesignBoxer Flat TwinEngine Four-stroke OHVModel Years 1951–1955 1951–1956Bore 68 mm / 2.68 in 72 mm / 2.83 inStroke 68 mm / 2.68 in 73 mm / 2.87 inDisplacementPower @ 5800 rpm / @ 5500 rpmCompression Ratio6.3:15.6:1 / 6.5:1Top Speed140 km/h (87 mph)150 km/h (93 mph)Curb Weight 190 kg (419 lb)Gross Vehicle Weight 355 kg (783 lb)Fuel Tank Capacity
See also History of BMW motorcycles Motorcycle fork BMW R68 List of motorcycles of the 1950s
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