Originally Posted by
icepick_trotsky
why does it seem like this sort of patent-related exclusivity didn't happen with other cycling technologies? Campy and Suntour both came out with indexing (though less successful) right after Shimano, and Campy introduced Ergos right after STI shifters.
IANAL, but "prior art," perhaps? Sturmey-Archer had indexed shifting as far back as 1903 (although is wasn't with a derailleur), and SunTour had a short-lived indexed shifting system in the late 60s and early 70s that was only marketed in Japan.