SM

Stefan Malcherek established the SM Workshop in Poznań in 1924, which manufactured a 50 cc auxiliary engine that could be fitted to a bicycle. It was mounted above the front wheel and drove the wheel by means of a roller. At the 1935 Poznań Fair he presented a 2hp two-stroke outboard motor which was well received. He adapted the 98 cc engine for use in a motorcycle and constructed a light motorcycle around the engine. The machine debuted at a competition organised by the Unia motorcycling club in December 1937. Although the competition was won by a German Phanomen machine, the SM was seen to be a good competitor. The machine went into production and was well received for its reliability.

SM supplied the engine to two other Poznań manufacturers: Nowaczyk Brothers' Bicycle Manufacture for use in their WNP 3-wheelers and Automatyk for their Zuch 98cc motorbike. Production ceased following the German invasion of Poland in 1939.