BMW Type 255

BMW Type 255 Kompressor (also known as the 500 Kompressor, RS 255, RS255 and Type 255 RS 500) was a supercharged boxer twin race motorcycle from the 1930s. A BMW 255 Kompressor was ridden to victory by Georg Meier in the 1939 Isle of Man TT and the first win by a non-British competitor in the premier 500cc Senior TT class.[3] A similar BMW 255 Kompressor machine was auctioned in 2013 for US$480,000, the second-highest price ever paid at auction for a motorcycle.[4][5][6]

BMW Type 255 Kompressor
ManufacturerBMW Motorrad
Also calledType 255 RS 500
PredecessorBMW WR 750
ClassStreet racing
Engine492 cc DOHC supercharged boxer twin with aluminium cylinders; magnesium engine block and supercharger casing[2]
Fuel: gasoline-oil mix
Bore / stroke66×72 mm[1]
Top speedc. 220 km/h (140 mph)[2]
Power60 hp (45 kW)[2]
Transmission4-speed, shaft drive[1]
Frame typeTubular steel twin cradle
SuspensionFront: Oil-filled telescopic forks
Rear: Rigid (1935–1936) Plunger (after 1936)[1]
Weight138 kg (304 lb)[2] (wet)


A Zoller sliding vane supercharger is bolted to the front of the DOHC engine, driven directly by the crankshaft, and is lubricated by castor oil added to the fuel.[1][2][7] It provided c. 15 psi (100 kPa).[1]


The machine set a number of race records, including the first lap over 100 miles per hour (160 km/h) at a major event, when Georg Meier won the Belgian motorcycle Grand Prix in 1939, and Ernst Jakob Henne's capture of the motorcycle land-speed record in 1936 on a model with a streamlined fairing.[1]


An example is on display at the BMW Museum in Munich.[8]

Further reading

  • 1939 BMW "Kompressor" Tourist Trophy 1–2 Victory June, 2009 BMW press release via WebBikeWorld
  • Extensive model information at Bonhams (prior to January, 2013 auction)
  • Blake Z. Rong (January 22, 2013), In Las Vegas, a gamble on BMW's Kompressor and McQueen's Husky: Bonhams Motorcycle Auction provides plenty of surprises, Autoweek


  1. Falloon, Ian (2003), The BMW Story: Production and Racing Motorcycles From 1923 to the Present Day, Haynes, pp. 24–26, ISBN 185960854X
  2. BMW News: A TT blast from the past, BMW Motorrad, April 5, 2013, archived from the original on September 10, 2014, retrieved September 10, 2014
  3. The Nazi TT – Hitler's 1939 Propaganda Victory in the Isle of Man page 73-80 by Roger Willis Motobusiness (2009) Quine & Cubbon Ltd ISBN 978-0-9562457-0-0
  4. "BMW brings together past and present on the Isle of Man", New Zealand Herald, August 22, 2014
  5. "Bikes sold at auction:1939 BMW RS 255 Kompressor", Hindustan Times, April 4, 2014
  6. d'Orléans, Paul (May 18, 2014), "Top 20 most expensive motorcycles at auction", The Vintagent
  7. Williams, Greg (September–October 2012), "The BMW RS 255 Kompressor: Making History Going Fast", Motorcycle Classics
  8. d'Orléans, Paul (December 28, 2008), "New BMW Museum, Munich", The Vintagent
  • Media related to BMW RS500 at Wikimedia Commons
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