1939-bmw-r12-military_1

The BMW R12 together with the later R75 epitomize the World War II military motorcycle celebrated by Hollywood and the popular press. Heavy but tough, fast enough, and essentially bullet proof.

From its beginning in 1935 to the R-12’s demise in 1942, BMW built nearly 30,000 R12s. The majority were civilian models conscripted in 1939 with another 10,000 units specially built for the Wehrmacht police and combat units. As an early adopter of electric arc welding, BMW was able to speed up considerably the manufacturing process – particularly welding frames – and the company never looked back. As it happens, the R12 was their most prolific BMW model until the R75/5 of the 1970s. Many believe the R-12 to be the first motorcycle with true hydraulically damped telescopic forks.

From the heat-soaked desert of North Africa to the frozen steppes of Russia, the R12, both as a solo and sidecar rig, performed the role of messenger carrier, field scout and even carried at high-speed infantrymen under fire on the front line. It could even plow through 10 inches of water. Eventually, the R12 was eclipsed by the purpose-built R75, or “war elephant” military machine launched in 1942.

The R12, with “R” BMW-speak for “roadster,” used a somewhat conventional air-cooled, 745 cc side-valve boxer motor in a pressed steel frame, with Cardan shaft drive and employed many high quality components. It was strong and reliable under all conditions. Because of this it was copied around the world once the fighting had come to an end.

This BMW is one of many military motorcycles from America, England and Germany on display at the National Motorcycle Museum. It is on loan from the Jill and John Parham Collection.

Specifications:

    • Engine: Boxer Twin, Side-Valve
    • Type: Air-cooled, Four Stroke
    • Bore & Stroke: 78mm x 78mm
    • Displacement: 745cc
    • Compression Ratio: 5.2:1
    • Carburetor: Amal
    • Ignition: Battery, Points
    • Lubrication: Pressurized, Wet Sump
    • Horsepower: 18HP
    • Transmission: 4-Speed, Hand-shift
    • Primary Drive: Gear Driven
    • Final Drive: Shaft Drive
    • Frame: Pressed Steel, Double Loop
    • Wheels / Tires: 3.50” x 19 / 3.50” x 19
    • Suspension: Telescopic / Sprung Seat, Rigid
    • Wheelbase: 54.5 Inches
    • Weight: 410 Pounds
    • Top Speed: 62MPH
2 replies
  1. Colonel
    Colonel says:

    The BMW R71 was the precursor to the R75. Germany sold the rights to the R71 to Russia,
    who’s version was then copied by the Chinese. Both Russia and China continued to make
    descendants of the R71, the Russian Ural and the Chinese Chang Jiang. BMW moved on
    with a better designed BMW R75 overhead valve machine.

    BMW didn’t have a monopoly with the German Wehrmacht, because they had serious competition
    from The Zundapp KS750 with side car. That bike was more stout and had hydraulic brakes on all 3 wheels. The Wehrmacht stepped in and “suggested” BMW and Zundapp standardize
    parts between the 2 bikes for the war effort.

    Reply

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