Radius, introduced circa 1990, was originally SunTour's 4th tier road group. It was intended for bicycles in the $500-$600 price range and competed directly with Shimano 500EX. It did later move up the hierarchy, as SunTour trimmed their road groups. . Radius, it was not widely spec'd. By this time, Shimano has taken over as the dominant Japanese component manufacturer. While most OEMs would offer a token SunTour model or two, it was usually the 3rd tier GPX or 5th tier Blaze. Offhand, the only model I recall being spec's with radius was the Raleigh Grand Prix, though I'm surte there were others.So, it is fairly rare but not valuable or particularly desirable.

While indexed, it is SunTour's AccuSift system, which often does not play well with SIS compatible freewheels. The intended AccuShift freewheels or cassettes can be difficult to find and expensive. However, there is always friction mode,