Hyperglide is the name given by cycling component manufacturer
Shimano to a sprocket design in their bicycle
derailleur tooth cassette systems. The design improves on their earlier Uniglide design (which used beveled/twisted gear teeth instead of ramps), and was introduced as part of a commercially viable
index shifting system. The individual sprockets on a Hyperglide cassette or freewheel are designed specifically to work with their neighbours. In order to ensure alignment of each sprocket with its neighbour, the
freehub has a narrow spline at one position, and each sprocket has a corresponding wide tooth on its inside face.
Photograph: Petar Milošević