Polish Motorcycles

Today in Motorcycle History

SM Motorcycles

SM 98, Wnp 98 i Zuch 98

At the spring fair in Poznan in 1935, considerable interest of the public and industrial circles was aroused by a small outboard motor for a kayak, developed by Stefan Melcherek and mass-produced in his factory "S M" in Poznan. These 2-horsepower motors were economical and reliable and became very popular, which meant that their production developed quickly and strengthened the manufacturer's market position. Melcherek, a modest constructor-craftsman, showed a lot of economic realism, because "observing for several years the unprecedented demand for mopeds, free constructor tax and driving license abroad, and recently also in Poland" - as he stated in an interview for the press, he decided to develop, on the basis of his manufacturing experience and equipment, also the production of engines for light two-wheeled vehicles. These engines were to be of his own design, a reference to the constructor's earlier (from 1932-33) creative activity, which resulted in a prototype motorcycle with a 500 cc engine, also successfully used in sports events.

The first "Setki" (hundreds) from Stefan Melcherek's modest factory, marked like all his products with the "SM" symbol, were presented to the public in December 1937 at a competition organized by the Poznan motorcycle club "Unia" and Antoni Kwiatkowski's "Wulgum" company.

Despite the terrible weather conditions, one of the motorcycles driven by the constructor achieved an average speed of 50 km/h in the 5 km road race, only 3 km/h slower than the winner, competing on the German Phenomena. SM 98 also performed excellently in other sports events held in 1938 - the "competition of hundreds" in Poznan, where famous competitors - Ignacy Lemanski and Jerzy Frass rode on Melcherek's motorcycles, and rally "100 miles around Poland" (advertisement of "Stomil" tyres) on the route Stryj - Kielce - Poznan, in which 2 motorcycles - one driven by the constructor - won two silver medals.

SM motorcycles were built only from elements of domestic origin (except for roller bearings), and the majority of components - including the engine, the frame and its accessories - came from the Poznan factory. The vehicle was characterized by construction solutions typical of small-engine motorcycles of the time, the so-called hundreds. A lightweight yet strong single tubular frame with stamped trapezoidal front forks, sprung by a central spring, housed a 98cc two-stroke engineand power of 3 hp at 3500 rpm. The two-part crankcase and the engine head were cast from light alloys, and the cylinder was made of cast iron with high thermal and mechanical resistance, and equipped with a one-sided exhaust outlet.

The engine was had a wet multi-plate clutch (transmission of drive from the crankshaft to the clutch by means of a chain transmission) and a gearbox with only two ratios, which meant that the maximum speed and especially acceleration of the SM 98 was slightly inferior to other Polish vehicles of this class, equipped with gearboxes with more gear ratios. The gearbox was controlled manually, directly, with a long lever located on the right side of the motorcycle. It also happened that the engines were equipped with foot shift mechanisms. Both the carburetor with a mesh, wet air filter and the 6V 15W magneto generator, placed under the engine flywheel, were the work of Stefan Melcherek. A properly developed vehicle structure, properly selected parameters of the engine, and a particularly well-developed carburetor, made the motorcycle very economical, as under full load it consumed no more than 2.5 liters of fuel per 100 kilometers.

However, the production of complete motorcycles by Stefan Melcherek's small factory was not very profitable, so despite great resistance, mainly emotional and prestige, the constructor was persuaded by Adam Paczkowski, a club friend (Poznan "Unia") and a well-known motor activist, and decided to devote his strength, skills and means of production exclusively for the further development of motorcycle engines. On the other hand, motorcycles - very similar in construction to the SM 98 - will be produced on the basis of cooperation based on Stefan Melcherek's engines, other "friendly" factories.

In the first phase of operation - in order to ensure sales for engines - Wiktor Nowaczyk (i.e. a motorcycle competitor), co-owner of Poznanska Wytwórnia Rowerów Braci Nowaczyk, was encouraged to apply SM 98 engines. The tests were successful and already at the Poznan Fair in the spring of 1939, not only engine-powered cargo tricycles with a load capacity of up to 200 kg with "independent suspension of each wheel by means of a piston system" and with a casing of the transport part made of "decapped sheets at the lines" were exhibited. streamlined" but also CIS motorcycles in two versions "popular" and "luxury". The differences were small, manifested mainly in the equipment and external decor. Vehicles of both types had Malcherek engines and identical frames made of structural steel pipes connected in a way characteristic for bicycles, using traditional connectors and brass soldering. Also the front fork (with a central spring) was made of tubes in a similar way.

When the bicycle factory of the Nowaczyk brothers expanded its production program, it was established in Poznan on the initiative of the excellent motorcycle riders Alfred Weyl and Ignacy Lemanski, the owners of the "Automatyk" factory (producing arcade game machines) and Adam Paczkowski, an assembly plant for two-wheeled vehicles. Motorcycles from the "Automatyk" company were built in cooperation with domestic sub-suppliers. The smallest of the planned family of three types was called "Zuch" and had an SM 98 engine. It was almost a copy of Stefan Malcherek's motorcycle, and differed from the CIS, among others. a system of connecting beams of the tubular frame (welded) and front fork pressed from pressed metal.

Zuch 98 was the only completed model of this company - vehicles with larger capacity engines of 250cc called Druh and 350cc - Champion, they were not developed before the outbreak of the war. The Nazi invasion also thwarted another useful production initiative. In 1939, Adam Paczkowski organized a motorcycle factory as a limited liability company as a union of the SM engine factory and the "Automatyk" assembly plant, with further shareholders up to 50% of the share capital. Larger scale production was to start in 1940.

Cubs and CIS could be purchased at the most famous motorcycle dealership - the "Wulgum" company at ul. Wielkie Garbary 8. Both producers and representatives of sales representatives understood perfectly well that sports successes are the best advertising, so the vehicles participated - successfully - in various events. First of all, it is necessary to note here the victory of Alfons Baranek on Zuch in the "II Meeting of Hundreds" in 1938, the completion of the "Six-Hour Winter Rally" by 3 Cubs in extremely difficult weather and road conditions, the team victory of 6 Cubs and the individual victory of Lemanski in the "III Meeting of Hundreds" " in April 1939 and the 1st place of the Zuchów team in the race of teams from three cities (Poznan, Bydgoszcz and Gdynia) in July of the same year.

It is significant that the SM 98 engines, thanks to their simple, functional design and high-quality workmanship, had gained a strong market position. SS-3-MR engines from the capital's "Auxiliary Factory for Aviation and Automotive Industry" A. Stinhagen and H. Stransky, were also to be used in light motorcycles, which he intended to produce in 1939 in Warsaw in the number of 300-400 pieces a certain Dynski.

Engine: two-stroke, single-cylinder type SM 98, chain drive to rear wheel
bore x stroke / displacement: 48x54mm / 97.7cc
Compression ratio: no data
Power: 3 hp at 3500 rpm
Clutch: wet, multi-disc
Transmission: two-speed, manually controlled, and in some versions foot operated
Ignition: magneto - generator - magneto type SM 6V 15 W locked with the engine flywheel
Frame: tubular, single, closed
Front suspension: trapezoidal fork
Rear Suspension: rigid
tyres: Polish Tyre"Stomil" 3.00 x 19"
Vehicle dimensions: unknown
Empty weight: unknown (probably around 65 kg)
Maximum speed: approx. 60 km/h
Fuel consumption: 2.5L/100km
permissible load: 1 person

Source: Polish History Archive

Note: There was also an SM factory in Warsaw (Wytwórnia Silników i Motocykli SM) - no relationship. See SM 500 1930~1935