You need to short the clutch lever position sensor plug at the handlebars. Otherwise you get CELs / no gear position indicator after swapping to non stock sprockets. I had to do the same thing. Same hack works for ('17-19) N650 and N400. Not sure about latest gen N650 you'd just have to try. The gearing CEL will clear itself after some number of restarts. Changing sprockets does NOT affect the relative wheel speeds front and back wrt the ABS ring sensors. That happens when you use odd tire sizes.