Originally Posted by
dddd
Shimano spent years developing SIS, knowing full well when the patent expired. Thus, when the first SIS gruppos appeared around the same time that Suntour's patent expired, Shimano was able to have slanted derailers ready for sale to give SIS the best performance (and market acceptance) possible.
This is THE important bit of strategy. Campagnolo instead in the early 80's was focusing on an alternative to what they had (and almost everyone had copied). A wasted effort, the most usable was the control rod seen on the Chorus, or was it Croce D' une? mechanism. Shimano also focused on a top down strategy, the top group got the new SIS first. In the past, new features would sometimes show up on downmarket groups first, like the first octolink crank attachment concept, that scheme did not serve them well.