Polish Motorcycles

Today in Motorcycle History

SHL M04 and M05 125cc Motorcycles


The first post-war motorcycles with the SHL mark appeared in 1947. The construction of these vehicles, with the symbol SHL M04, was based on the pre-war SHL 100 model. The M04 motorcycle was equipped with an SOI xxx engine with a displacement of 125cc litre, which was supplied from the State Aviation Works No. 3 in Wrocław (later WSK Wrocław). The low curb weight was due to the simplicity of the design. The vehicle had no battery and the rear wheel was rigidly attached to the frame. The motorcycle was equipped with only a single seat for the rider, which was suspended on two coil springs. Until 1952, a total of 18,505 M04 motorcycles were made in Kielce, after which their production was transferred to the Warsaw Motorcycle Factory established in 1951.

Engine - Type SOI, spark ignition two-stroke, backwash rigidly mounted in the frame of the motorcycle Cylinder diameter 52 mm, piston stroke 58 mm Number of cylinders l. Displacement 123 cc, compression ratio 6. Maximum power 3.0 kW (4.0 hp) at 4250 rpm. The maximum torque of 7.36 Nm (0.75 kGm) at 3000 rpm. The engine block, cast in light alloy, divided in a vertical plane, was also the housing of the clutch, gearbox and magneto. Ribbed cast iron cylinder. Ribbed light alloy head. Crankshaft forged, folded, supported on four ball bearings. Forged connecting rod, roller bearing in the foot. Light alloy cast piston with a slightly convex crown and two sealing rings. Piston pin embedded floating. Piston timing. Control of the charge flow through the edges of the piston. Two through channels. Mixed lubrication, fuel-oil ratio 20 : l. Forced air cooling. Power supply: horizontal carburetor, Amal E68/16 with a throat diameter of 16 mm, mounted directly on the cylinder. Flat air filter, made of metal mesh, mounted on the carburetor. Starting shutter on the air filter. Dry weight of engine with accessories and gearbox approx. 20 kg.

Electrical system - Rated voltage 6 V. Spark ignition. Flywheel magneto, mounted on the right crankshaft journal. The generator magneto stator consisted of: ignition coil, lighting coil and circuit breaker. Static ignition advance 27° before TDC. Spark plug, M14X1.25 thread, 175 calorific value (Bosch). 17W AC generator. Battery not included. Headlamp with high beam, symmetrical low beam and city light. Rear lamp with position light and license plate light. Sound signal in the form of an air horn.

Drive system - Friction, wet, three-disc clutch with cork inserts, located on the left side of the motorcycle. Six helical compression springs. Cochlear engagement mechanism. Transmission from the crankshaft to the clutch with a single 1/2" X 5.2, 35 link roller chain. 2.27 gear ratio. Three-speed gearbox. Constantly meshing gears. 16, IIb-1.49, IIIb-1.00 Gear shifting by foot lever, located on the left side of the engine Power transmission to the rear wheel with a 1/2" X 5.2 mm single row roller chain, 114 links. Gear ratio 3.42.

Chassis - Cradle frame, closed, double, welded from steel profiles with a C-section, pressed from sheet metal. Two ball bearings embedded in the head tube. Front wheel suspension: on a trapezoidal fork, with a central barrel-type coil spring, two friction shock absorbers, with adjustable pressure. Rigid rear wheel suspension. Spoke road wheels, 36 spokes with a diameter of 3.1 mm in each wheel. 1.7X19" rims made of steel. Steel tubular hubs with two ball bearings. Non-thrust wheel axles. Tube tyres 3.00X19".

Braking and Steering - Mechanically actuated, independent, drum brakes. Brake drums made of pressed pressed metal. The inner diameter of the brake drums. 125mm. The front (hand) brake is controlled by a Bowden cable, the rear (foot) brake is operated by a rigid pull rod with smooth regulation, located on the right side of the motorcycle. Steering wheel made of steel tube, adjustable in position. Winding type "gas" twist handle. Handbrake and clutch levers pressed from sheet steel.

Body - Shallow mudguards pressed from pressed metal. Fuel tank welded from steel stampings. Three-position fuel tap. The riders's seat is made of pressed pressed metal, covered with leather, pivotally mounted in the front part, supported on two coil springs. Luggage rack placed on the rear mudguard, based on brackets screwed to the frame gusset plate. Tool box, in the form of a cylindrical can made of pressed metal, attached to the frame under the steering wheel saddle. Riders's footrests made of steel tubing, with rubber pads and brackets connecting the footrests with the frame. Central base, pressed from pressed metal. Partial drive chain cover (top). Lower exhaust system with removable muffler, located on the right side of the motorcycle.

Dimensions - Wheelbase 1295 mm, overall length 2025 mm, width 690 mm, height (unladen) 900 mm, riders's seat height 665 mm, ground clearance 150 mm. Front wheel advance 60 mm.

Weights - Motorcycle 80 kg, permissible load 130 kg. Permissible total weight 210 kg.

Capacities - Fuel tank 10 dm8 (including 2 litre reserves), gearbox 0.5 litre.

Operating data - Top speed 67 km/h. Fuel consumption 3 litre /100 km. Air pressure in the tyres of the front wheel 0.06 MPa (0.6 kG/cm2), rear wheel 0.10 MPa (1.0 kG/cm2).


After the end of the production of Sokołów in the National Automobile Works No. 2 in Warsaw, preparations began to take over the production of motorcycle chassis and engines from other plants. In August 1951, the plant's name was changed to the Warsaw Motorcycle Factory, and in mid-December motorcycle assembly was launched. Initially, these were the SHL M04 models, the same as those manufactured in Kielce, and then a modernized model marked as SHL MOS was introduced to the assembly line. The main difference was the replacement of the trapezoidal front fork with a telescopic fork (without oil damping). The design of this fork was developed in the years 1949/1950 and proven in numerous rallies and races in which the 5'HL factory teams took part. The MOS motorcycle was a transitional model, until the start of production of a new vehicle under the WFM brand. Production of the SHL M05 model ended in 1954.

Engine - Type SOI, spark ignition. Data as for the SHL M04, with the following changes: Power supply: horizontal carburettor, Amal E 68/18, throat diameter 18 mm, mounted directly on the cylinder. Dry weight of engine with accessories and gearbox 20.5 kg.

Electrical installation - Data as for the SHL M04.

Drive system - Data as for the SHL M04.

Carrying system - Data as for the SHL M04, with the following changes: Front wheel suspension on telescopic fork, without oil damping. Double springs. Rubber covers in the lower parts of the fork tubes. Fork shelves made of pressed pressed metal. Wheel hubs made of tubular steel with two ball bearings. The axle of the front wheel is esophageal, the rear wheel is not esophageal.

Braking and steering - Data as for the SHL M04.

Body - Data as for the SHL M04, with the following change: lower exhaust system, with a non-removable silencer, located on the right side of the motorcycle.

Dimensions - Data as for the SHL M04.

Weights - Data as for the SHL M04.

Capacities - Data as for the SHL M04.

Operating data - Data as for the SHL M04.

Source: Polish History Archive