Originally Posted by
WhyFi
Yeah, I would think that the clutched RD would be 95% of it. Maybe a chainring/crankset for 1x. I don't see the rest
They totally redesigned the STI levers. Changed the crank design to allow more clearance for tires which required an update to FD geometry -- the chainrings are 2.5 mm farther from the frame than before. Stuff like that.