BMW Type 255

BMW Type 255 Kompressor
ManufacturerBMW Motorrad
Also calledType 255 RS 500
Production1935–1939[1]
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)
Georg Meier riding the 1939 BMW Type 255 Kompressor at the 1989 Isle of Man TT Race
Supercharger-engine-gearbox unit construction assembly

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]

Supercharger

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]

Records

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]

Today

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

References

  1. ^ a b c d e f g Falloon, Ian (2003), The BMW Story: Production and Racing Motorcycles From 1923 to the Present Day, Haynes, pp. 24–26, ISBN 185960854X
  2. ^ a b c d e 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, archived from the original on September 10, 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