This BMW RS 255 Kompressor was constructed in the 1980s by ex-works racer Walter Zeller and BMW engineer Gusti Lachermaier as a demonstration bike for Zeller. It was built from original parts sourced from BMW.
BMW had began experimenting with supercharging in the 1920s with the supercharger mounted above the transmission. In 1935 the Zoller supercharger was moved to the front of the motor, which now sported DOHC heads.
The RS 255 made its debut at Avus and was campaigned up until the early 1950s in the German national championship (which continued to allow forced induction, which had been banned when GP racing resumed in 1949).
Perhaps its greatest triumph was winning the 1939 IoM Senior TT with Georg Meier becoming the first non-British rider to win the event.
Several World Speed records were set by the 255 in 1936 by Ernst Henne including a run of 272 km/h. Output was normally around 50-60 hp but that could be increased to 80 hp by upping the boost, while in road race trim weight was 138 kg.
MCNEWS.COM.AU is a specialist on-line resource that provides motorcycle news for motorcyclists. MCNews covers all areas of interest for the motorcycling public including news, reviews and comprehensive racing coverage.