Vintage SunTour

SunTour grew out of Maeda Iron Works, a Japanese freewheel maker founded in 1912. In 1964 its Grand Prix rear derailleur introduced the slant parallelogram, which tilts the derailleur so the guide pulley follows the freewheel profile as it moves. Disraeli Gears gives the US patent as 3,364,762, filed in 1964 and expired in 1984. Sheldon Brown's SunTour history says competitors adopted the design immediately after it expired, and Shimano's 1984 Dura-Ace 7400 was one of the first. Sheldon Brown dates the Cyclone to 1975, Superbe to 1977 and Superbe Pro to 1981, and credits SunTour with the Power Ratchet friction lever. SunTour's AccuShift indexing came in the second half of the 1980s and trailed Shimano's SIS, and Sheldon Brown says most of its problems were fixed only by 1990. SunTour stopped making components in March 1995, and SR (Sakae Ringyo) bought the name, but none of the component designs survived.

5 references tracked.