Helios (motorcycle)
The Helios was a motorcycle that Bayerische Flugzeugwerke built in 1921 and 1922. In 1923, BMW briefly continued production.
technology
The machine had an air - cooled, side-controlled two - cylinder boxer engine from BMW with magneto ignition , type M 2 B 15, which was installed transversely; that is, the crankshaft was perpendicular to the direction of travel and parallel to the axes of the front and rear wheels. As a result of this installation, the cylinders did not protrude laterally into the airstream, as in later BMW motorcycles, but were directed forwards and backwards. The flywheel ran freely on the left. The engine had a displacement of 494 cm³ with a bore and a stroke of 68 mm each. It developed 6.5 hp at 3000 rpm. The power was transmitted to the rear wheel via a single-disc clutch, a manual three-speed gearbox and a roller chain. The shift lever was guided in a setting on the right of the tank.
The approximately 2.60 m long Helios had a tubular steel frame with a so-called plug-in tank, which was inserted between two frame tubes behind the steering head . The front wheel was guided in a pendulum fork , while the rear wheel , which was equipped with a block brake , was not sprung. There was no front brake.
End of production
After the takeover of Bayerische Flugzeugwerke by Camillo Castiglioni and the re-establishment of Bayerische Motoren Werke Aktiengesellschaft in June 1922, production of the Helios was soon stopped. In autumn 1923 BMW presented the BMW R 32 with a longitudinally installed motor and shaft drive to the rear wheel, the forerunner of the later cardan shafts .
source
Wolfgang Zeyen, Jan Leek: BMW motorcycles since 1923 . Motorbuch Verlag, Stuttgart 2004, ISBN 3-613-02401-2 , pp. 20, 21 and 24.