In many countries, these bikes were known as RDs, but in North America and Australia they were called the RZs. In Australia, England, Canada, and the USA the Yamaha RD series (RD-60, RD125, RD-200, RD250, RD350, RD400) from which the later RZ/RD were descended, were first released in the 1970s as air-cooled two-strokes. In 1980 the bikes had a redesign using ideas Yamaha gained from two-stroke Grand Prix and production race experiences. They also became liquid-cooled and had an 'LC' appended to the name to designate this e.g.: RD350LC - some people referred to them as the "Elsie". The Elsie is the link between the earlier air-cooled RDs, and the later power valve (YPVS) equipped RZ series. The most common capacities sold in Australia were 250 cc (maximum capacity allowed for new road riders) and 350 cc.