Originally Posted by
grumpus
Those are the major evolutionary steps that saw chain go from 2x5 transmission to 1x12.
Evolutionary. Sure. But our friend Andrey seems to think there was some monumental technological breakthrough 30 years ago that somehow eliminated the possibility of the chain going from the extreme inboard cog on the wheel to the extreme outboard chainring on the cranks. Without a hint of incredulity, he even calls this major development
"the most important objective of all bicycle drivetrain design in the world for the last 30 years." Not more gears. Not smoother, more-accurate shifting. The ability to cross-chain has been the gold standard of drivetrain component engineers for three decades.