my 3 highest gears are really rough,can feel it through the pedals when pedaling!!have checked everything.all teeth ect look ok.have tried altering chainline with spacers to no avail.there is slight play in the rear derallieur but not that bad.
anyone any ideas??
it is a double front with nine rear sram x9 btw

I had something similar with an XT mech and just adjusted the little philips screw on the rear mech that presses against the rear mech hanger (not the low-high adjusters).

Essentially it was moving the top jockey wheel away from the casette.

Yeah that could be the b-screw. If it's not right the top jockey wheel can rattle against the larger cogs in the cassette.

last few sprockets on the wrong way round on the rear cassette?

The smoother sides should be facing the hub

have tried the b screw it seems ok.ill check the sprockets but i dont think so as its a new noise and ive not had cassette off.

gavgas you are a star!
last 2 on wrong way.what a fud!! must have been like that for ages!
cheers 😛

😉

take that back.it was on right!!
any more ideas 🙄

😕

just accept bikes are a pain in the ass!