Two years ago I build a bike (flat bar) with SRAM 1x11. Around a month ago the rear-derailleur broke (guide pulley broke).
I bought a new rear derailleur: Shimano 105 RD-5800-GS.
After installation shifting got bad. The rear derailleur moves to far for each click, so sometimes it changes two gears for one click. It only takes 8 clicks to move the chain from the inner sprocket to the outer - and only 8 clicks to move it back. In other words it seems like the derailleur moves around 5 millimeters instead of 4 millimeters.
I have another bike (road bike) with Shimano 105 5800 group (2x11). I tried to take the wheel and the rear derailleur from that bike to the bike with the problem. It did not help - problem was the same.
I bought a new shifter: "Shimano XTR SL-M9000-R Rapidfire Plus Shifting Lever - 11-speed". Problem was still the same after installation. (Cable was also changed).
I bought and installed a new derailleur hanger. Problem is still the samme.
I have not had any crashes.
I think I have tried everything. Any ideas, what can I try ?