Tuesday, February 8, 2011


DAK BMW R75 from the 15th Panzer Division at the El Alamein Military Museum. Thanks to J. Porter

The original was a BMW R75, first produced in Germany in 1941 specifically for military use, primarily used with a SideCar. These military motorcycles were so reliable and successful (as also past/future models) in all climates from freezing snow to blistering desert that replica spin-offs were produced by disassembly and replication of captured BMWs in many other countries such as Russia, Korea, Japan, & China (many of these survived the war and are in museums).

In the early 1940s plans were even stolen from the factory in an attempt to unlock the "secret" of their construction (metallurgy and specific part manufacturing techniques in addition to complete hand-craftsmanship and assembly played a huge role in BMW durability and longevity).

Even Harley-Davidson produced a similar replica bike near the end WW-II for military use (yes...a twin cylinder Harley which was NOT a V-Twin but a horizontally opposed BMW replica: HD doesn't like to talk about this model very much!).

High dectailed scale model from ESCI
1923 was the first year BMW produced a motorcycle, taking an existing aircraft engine (their main manufacturing business then) and mounting it in a motorcycle frame with a shaft drive. Their factory logo (the circle cut in quadrants of blue/white with black border & BMW lettering) was created to be representative of a propeller spinning with the colors of Germany in the background to acknowledge their aircraft engine roots.

  • Model R75
  • Motor Type BMW Type 275/2
  • Cylinders 2
  • Bore/Stroke 78mm x 78mm
  • Displacement 745cc
  • Compression 5.6-5.8:1
  • Output 26Hp@4,000rpm
  • Valve System Overhead
  • Valve Drive Pushrods & Rockers
  • Ignition Magneto
  • Dynamo 6Volt/70Watt DC Generator
  • Ignition Timing Manual Advance
  • Spark Plugs Bosch W 175 T 1
  • Engine Lube Force-Feed Circulation
  • Oil Pump Positive-Displacement Gear
  • Carburetors Graetzin Sa 24/1 & Sa 24/2
  • Clutch Single-Disc Dry
  • Gear Ratios 1:4.46, 1:3.22, 1:2.54, 1:1.83, 1:1.67, 1:1.24, 1:1.21, 1:0.90
  • Reverse = 1:3.3, 1:2.41
  • Final Drive Ring/Pinion Differential (Allowed SideCar Wheel To Also Be Powered If Attached)
  • Suspension Rear = Rigid, Front = Hydraulic Dampened Telescopic Forks (Invented by BMW!)
  • Brakes Drum Front/Rear
  • Tires 4.50 x 16" Metzler
  • Length 2400mm (98") With SideCar
  • Width 1730mm (70.6") With SideCar
  • Height 1000mm (40.8") With SideCar
  • Weight 420Kg (980Lbs) Unladen
  • Fuel Capacity 24 Litre (6.3 US-Gallons)
  • Consumption 11.7-15.9 km/ltr (27.5-37.4 mpg)
  • Top Speed 95 km/h (59 mph)

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