PUCH LM – year 1923
Manufacturer: Puchwerke Aktiengesellschaft, Graz, Steiermark, Austria
After a break caused by the outbreak of the First World War, Puch motorcycles did not appear on the market until 1923 year. Unlike other manufacturers, the company was not satisfied with the production of pre-war models and prepared for production a new motorcycle with an unconventional two-cylinder, two-stroke engine, the two pistons were seated on a common one, forked connecting rod.
The new model was marked with the symbol LM - light motorcycle. Its designer was Eng. Giovanni Marcellino, known for developing an engine concept with two pistons mounted on one connecting rod, already in the Italian company Garelli, where he worked then. The Puch engine, however, had an improved design: two cylinders and two pistons with a common combustion chamber and a common forked connecting rod. The engine, however, operated as a single cylinder, because one of the pistons controlled the flushing of the cylinder, the other with the exhaust outlet (with this, that the exhaust piston was ahead of the flushing piston during operation). Thanks to this solution, better filling is achieved and losses of charge exchange are reduced. Small engine capacity, because only 123 cm3, and hence, low power - 1,5 kW (2 KM) at 2500 RPM allowed for achieving (on a level road) speeds up to 60 km/h, even though the unladen weight of the motorcycle did not exceed 42 kg. The rear wheel was driven by a chain. Inside the rear wheel hub was a two-stage freewheel planetary gear, at the same time fulfilling the function of a clutch.
In the first year of production, it was sold immediately 2500 pieces of this model, that is the company's year-round production. The commercial successes allowed for further work on improving the motorcycles and preparing a new one, stronger model 175 cm3.