Originally Posted by
smd4
So why don’t you explain the revolutionary technological changes in chain-driven, front-and-rear derailleur-equipped bikes that happened 30 years ago that eliminated the concept of cross chaining?
Further back than that: the Sedisport bushingless chain with chamfered side plates was introduced in 1978. Since then riveted pins have been added to the mix to make narrower bendier chains that don't fall apart, but which require special joining links. Those are the major evolutionary steps that saw chain go from 2x5 transmission to 1x12. The narrow-wide chainring may also merit a mention.