The Wooler was always one of the strange machines that make motorcycles so interesting.
The industry is peppered with individuals who saw their way as being correct and often refused to deviate a fraction from their chosen path. They seldom built many machines, and those they did produce were frequently troublesome, but we all gained by the excitement they generated.
The engine (1926) was the feature of greatest interest and was laid out as a transverse-four, the cylinders on each side being one above the other. This alone was far from normal, but really unique was the way in which they were connected to the crankshaft, for this was based on the beam engine. Capacity was 500cc, and overhead valves were used.
The crankshaft ran along the machine, below all the cylinders, and was of a single-throw design. In fact, for the prototype, a modified assembly from a 150 cc New Imperial was used. Above the crankshaft was a T-shaped beam, which was pivoted at the junction of the leg and arms, this axis also Iying along the machine. A master con- necting rod joined the end of the T-leg to the crankshaft, so as this rotated, the beam oscillated. The arm of the T was set vertically, and each end was attached to two connecting rods, which pointed in opposite directions and ran out to the pistons. Thus, these moved in pairs, and the two pairs moved in opposition.
Roy Bacon 1989