Originally Posted by
theblackbullet
Far as I can tell, that page is simply wrong.
Unless there’s some alternate cable routing for the rd-x9-a1 it seems to be only 1:1 and not “exact actuation”. I’ve fiddled with one at the shop and can’t deduce any way to alter the pull.
It doesn’t help that none of the tech docs that SRAM links to on that page have contain any mention of that derailleur.