1968, SUZUKI RP68 (50cc), a masterpiece of fine watchmaking
In 1967, the FIM made it known that from the following year (inclusive) the 50cc engines of the World Road Racing Championship could only be single-cylinder with a gearbox with a maximum of six speeds. It was the end of an era in which engines multiplied the number of cylinders in order to obtain power, and this solution implied dealing with minimum usage ranges (in rpm) that forced the number of gear ratios to be multiplied.
When the FIM published this rule, SUZUKI already had the development of the prototype, to be used in the following year, at an advanced stage. The RP68 was ready at the end of 1967 but never got to compete, it was an extraordinary motorcycle, not only for the complexity of mechanical construction, but also for the performances achieved. The engine, 2T, had 3 liquid cooled cylinders, intake by 3 rotary valves, developed a maximum power of 19 hp at 20,000 rpm and had a utilization range of 500 rpm (!!!) which implied a 14-speed gearbox, dry clutch and a maximum speed of 200 km/h!!!