Polish Motorcycles

Today in Motorcycle History

Sokol 600 RT M 211

In 1934, production of the previously developed heavy motorcycle CWS M 111 had begun, an independent Motorcycle Department was organized in the Office of State Studies of Zakłady Inżynierii in Warsaw. The head of this department was Eng. Tadeusz Rudawski, and his collaborators were, among others, engineers Zbigniew Możdżewski and Jan Gebler, as well as specialists from the team which developed the CWS M 111.

The military's demand for motorcycles was not high at that time and did not exhaust all the construction and production capacity intended for their production. Rational taking advantage of the factory's production capacity in this respect required the design of a lighter motorcycle, adapted to the requirements civilian riders, and at the same time durable enough to be able to perform auxiliary military tasks.

Two versions of the civilian motorcycles were planned - touring and sports. The development of the first was entrusted to Eng. Rudawski, and the other to Eng. Możdżewski.

The construction work proceeded quickly, but under the pressure of the military circles, it was considered the most expedient to release a touring motorcycle. In less than two years, designs were developed, prototypes were built and tested, and the production technology was prepared.

The first series of machines designated Sokół 600 RT (Rudawski - Turystyczny) went on sale in the second half of 1935.

The construction of the tubular frame and front suspension with a trapezoidal fork clearly echoed the design of the Ariel 500 SV, Rudawski's favorite motorcycle, on which he achieved numerous sports successes in his youth.

The Sokol 600 RT engine was an original concept of the designers, in which they applied innovative technical solutions. For example, one could replace circulating lubrication, e.g. with oil injection into the cylinder branch and an oil tank in the clutch housing, the engine suspension on rubber-steel bushings that emit vibrations generated during its operation, and the gearbox, constructed as a separate unit, but placed in a special compartment within the engine cases. This ingenious design had all the advantages of a monobloc and at the same time eliminated its disadvantages. In the event of failure, the entire assembly could be disconnected without troublesome engine disassembly, and when the primary chain grew slack, tension adjustment was carried out by turning the eccentrically mounted gearbox. These solutions, simplifying operation and facilitating operation, have become PZInż patents.

Concern for the rider can also be seen in the design of the chassis. Replaceable wheels disassembled without brake drums (QD), adjustable saddles - with the possibility of using 3 types of springs, depending on the weight of the rider and passenger, and foot (but with two levers, without the so-called automatic) and manual shifting, these are just selected examples. It should be added that in order to extend the service life, the drive chain was drip-lubricated with engine oil and worked in a cover.

Motorcycles were produced almost entirely from domestic components, as a product of PZInż. and specialized partners. From import only bearings, carburettors (Amal 26 or, less frequently, Graetzin M. 26) and generators (Bosch) or magneto-dynamo (Miller) - depending on the type of electrical installation - were supplied.

The Sokół 600 was characterized by purposeful design, reliability and good off-road properties, and as a result became a very popular machine soon after entering the market. Motorcycles of this brand successfully took part in many national sports events, as well as in the international star meeting in Berlin in 1936. The greatest achievement, however, was the conquest of two Sokoły 600 (and one type 200) of the Tatra Mountains of Kasprowy Wierch. The authors of this feat, which has not been repeated to this day, were two well-known employees of PZInż. - Tadeusz Heryng and Józef Jakubowski and the famous motorcyclist Józef Docha.

Sokół 600 had an original off-road version. It was a three-wheeled single-track vehicle with two powered rear wheels. Two prototypes were made, which showed good traction in mud and sand, while on the road, especially at higher speeds, handling became difficult and even dangerous. However, the military showed no interest in motorcycles, so no further trials were conducted.

Technical data

Engine: four-stroke, single-cylinder, chain drive to the rear wheel.

Bore x stroke / displacement: 83 x 106 / 575cc

Compression ratio: 4.6:1

Power: 15 hp at 3900 rpm / minute

Clutch: wet, multi-disc

Transmission: three-speed, manual or foot operated

Ignition: magneto or battery and coil

Frame: tubular, double, closed

Front suspension: Trapezoidal fork with friction shock absorbers

Rear Suspension: rigid

tires: Polish Tyre "Stomil" 4.00 x 9

Length Width Height: 2160 / 780 / 1000mm

Wheelbase: 1430mm

Empty weight: 146 kg

Maximum speed: 110 km/h

Fuel consumption: 4L/100km

oil consumption: 0.1L/100km

Source: Polish History Archive