Sram drive train question

[Jerulator]

I recently upgraded the sram nx derailleur to a gx model. My question is do I need to replace the cassette to a gx compatible ? It works with the existing cassette but not as smooth as I’d like. Mine is an 11 speed.

 

[Jerulator]

 

[Stihldog]

As long as your new GX derailer is an 11 speed, you should be okay . But is your 11 speed cassette wearing out? Or your chain? Proper/fine adjustments may be necessary when replacing drivetrain parts. Barrel adjustment to “zero” (screwed in) might be a good start.

Maybe you’ve done this but, store your bike with the dropper in the extended position if possible. …and that’s a cool tire pump supporting your bike.

 

[Mikerb]

You can run any of the SRAM range mechs as long as they are 11 speed to match your cassette. Have you gone through the set up process for the mech?
Put the barrell adjuster in a mid position so that there is adjustment if needed later on. Feed the cable into the mech and pull tight by hand before tightening off to secure. Then set the high and low stops...........top jockey in line with the outside face of the smallest cog, then directly in line with the biggest cog. Then adjust B tension........easiest way to start with is 10mm gap between top jockey and biggest cog. Test gear change from smallest cog to 3rd smallest ...up and down. Adjust barrel as required.....anti clockwise to add cable tension....clockwise to ease cable tension. One or two clicks at a time. Now test gear change from largest cog to next 2 cogs. B tension can be fine tuned here because it will depend on the age of the chain.........a fairly worn chain will need a slightly smaller B gap.