Originally Posted by
RobbieTunes
...1989 was the only year of Suntour GPX, a shame, because a refinement of GPX would have been a formidable down tube drivetrain, had they decided to polish a bit, go with 53/39, and move to freehub stuff. Probably too much to take on, given their financial position and Shimano moving into the bike components aggressively...
SunTour continued to offer GPX in 1990 & 1991. Both years had freehub and Command Shifter options. It didn't sell well and WSI under its new ownership went 100% Shimano, but it was available.