Page:The Cycle Industry (1921).djvu/124

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In 1909–10, Alfred A. Scott, a Bradford engineer, brought out a two-cylinder, two-stroke bicycle, and it immediately gained prominence. The design of engine and bicycle was clever, and as the modern patterns have won the Tourist Trophy race in the Isle of Man on more than one occasion, it will be recognized that Mr. Scott is more than usually learned in motor cycle construction.

Two-stroke engines had existed before, notably on the Lepape or Bechrone motor cycle, and were largely used in the United States and Canada for boat propulsion in smooth inland waters, but the Scott was different from these. As it possessed two cylinders and the impulse strokes in each occurred alternately at each revolution, the power strokes took place twice during one revolution of the crank shaft, the turning effort being, therefore, equal to that of a four-cylinder, four-stroke engine.

At this period in the history of the motor cycle practically every cycle maker had one or more motor bicycle models to offer, and many who had discontinued their manufacture re-started. In addition, many purely motor cycle concerns were launched to make nothing but petrol engine propelled machines. The success of the Scott caused a number of makers to turn their attention to the two-stroke engine, which was found to be particularly suitable for small light machines, and the little two-strokes were produced in large quantities at lower prices than had obtained previously. The motor cycle now began to settle down to three classes of machine. 1. A small two-stroke lightweight for solo riding, with an engine of 2 H.P., to sell at about £30 to £40. 2. A medium weight four-stroke, single or twin cylinder machine for serious touring, with an engine up to 3½ H.P., selling at £50 to £60. 3. A heavier