Shimano developed its first derailleur in 1954 adopting a sliding shaft mechanism and a volute spring; however, Shimano was forced to pull out of manufacturing derailleurs due to the decline of the short-lived cycling boom. In the 1960s, sports bikes for leisure and other purposes saw their heyday. Following the development of an internal geared “3-speed hub,” Shimano again worked to develop derailleurs. In 1965, Shimano released SHIMANO, a derailleur that adopted a pantograph mechanism, which became the basis of the present mechanism. Shimano originally developed the product to fit the use environment in Japan. From this on, Shimano developed a great deal of technical expertise in derailleurs, expanding its share both in the domestic and overseas markets.