Junak WB1/WB3

 

 

 

 

Make Model

Junak WB1/WB3

Year

1959 - 65

Production

8500

Engine

Four stroke, single cylinder, OHV

Capacity

349 cc / 21.3 cub. in.

Bore x Stroke 75 x 79 mm
Compression Ratio 7.0:1
Cooling Air/Oil cooled
Lubrication Dry-sump

Ignition

Magneto

Battery

14 Ah, 6V

Dynamo

45 W

Starting

Kick-start

Clutch

Multi-plate clutch with cork inserts working in an oil bath

Max Power

14 kW / 19 hp @ 6000 rpm

Max Torque

27.5 Nm / 2.8 kgf-m / 20.3 ft-lb @3800 rpm

Transmission

Four-speed constant-mesh

Final Drive

Chain

Gear ratios

1st 3.04 / 2nd 1.97 / 3rd 1.29 / 4th 1.00:1
Frame Double, cradle-type, welded throughout of tubing, provided with holders for side car mounting.

Front Suspension

Fork with coil springs telescopic shock absorbers

Rear Suspension

Independent rear wheel suspension on single wishbone , cooperating with  7- leaf spring  positioned transversely;

Front Brakes

Full hub width, of expander shoe type, hand operated

Rear Brakes

Full hub width, of expander shoe type, foot operated

Wheels

Wire type, with full width hubs made of light alloy, interchangeable (also with side-car wheel). Both wheels with quick-detachable spindles

Front Tyre

19 in

Rear Tyre

12 in

Front Rim

89 mm / 3.5 in

Rear Rim

89 mm / 3.5 in

Trail

72 mm / 2.8 in

Overall Dimensions

Length:  2195 mm / 86.4 in

Width:    1490 mm / 58.7 in

Height :  1120 mm / 44.1 in

Dimensions of Sidecar

Length:  1800 mm / 70.9 in

Height:   1120 mm / 44.1 in

Rear Track

1020 mm / 40.2 in.

Wheel Base

2010 mm / 79 in

Seat Height

755 mm / 29.7 in

Ground Clearance

170 mm / 6.7 in

Wet Weight (incl sidecar)

260 kg / 573.2 lbs

Weight of Sidecar

67 kg / 147.7 lbs

Load Capacity

210 kg / 463 lbs

Fuel Capacity 

17 l / 3.9 US gal

Average Consumption

5.7 l/100 km / 17.5 km/l / 41.3 mpg

Top Speed

85 km/h / 52.8 mph

Source

Article by T. Tomaszewski in „Świat motocykli” 2003.

Szczecin Motorcycle Factory developed and started to produce in 1959 a M07 with passenger side loader , branded as the WB1 and was later followed by the WB3. In essence these two motorcycles are the same - the WB1 is based on the M07 and the WB2 on the later model M10.

Passenger carrier arrangement

The sidecar, made ​​of steel , was equipped with a windshield of perspex.
 

The frame of welded steel tubes suitable for four-point connection to the motorcycle, equipped with two ball joints and two tubular struts .

 

 Castor spoked rim size 1.85x19 . " Tubed tires with dimensions 350x19 " .

 

The sidecar, made ​​of steel suspended for rotation in the front part of the frame and on the back of the two stretched rubber rings . Seat covered with vinyl, and was equipped with a reclining backrest , and housed a luggage bay . The sides were equipped with soft armrests. A sheet black canvas covered the sidecar.