Quick final update. Had a GX derailleur in the spares bin that I pulled off a bike before we sold it, so I grabbed it and swapped it over. Voila, perfect shifting. So yeah, seems like an issue with that NX derailleur. The one on her sister's bike is working fine for now.

I'd sworn off SX after I broke a derailleur in two riding my Stumpy through a leaf pile, had higher hopes with NX. Guess we will just upgrade as needed.

 

Glad you found a solution.

That NX stuff wears out quickly. It works fine when new. Good enough for the demo ride before you buy it. Friends don't let friends ride NX.

BTW, I'm selling an NX shifter, RD and cassette if you are interested. I just have to work on my sales skills I guess .
I replaced the NX s$$t with Sunrace cassette and Deore RD and XT chain and the difference is night and day. Not as fully perfect as a real HG+ (requires MS Shimano cassette), but still great.

 

Shimano has always had great performing parts at lower levels, they just get heavier and less cool or "blingy" as you go down. Most of the time Deore performs just as good as XT and its cheap. The same can not be said about SRAM, as good as their top stuff is, everything below GX is garbage, and I really cant understand how they are not embarrassed to put that junk out.

 

everything below GX is garbage, and I really cant understand how they are not embarrassed to put that junk out.

I don't think so. It does look flimsy and the cassette and chain are junk but the derailleurs and shifters surprisingly aren't too bad.

 

NX drivetrains obviously aren't top notch but despite all the slop in their derailleur pivots they can be adjusted to shift just fine. If there are issues always check the derailleur hanger alignment first. B-screw adjustment is very important too and should be performed with the rider on the bike.

 

Maybe the shifter? Hanger checked?

Get a Deore RD and XT shifter and throw that NX stuff out. Those SX/NX things are just placeholder so you can ride home to order the hardware you actually want

 

Get a Deore RD and XT shifter and throw that NX stuff out.

Shimano shifter and derailleur works surprisingly well on an NX cassette which is good because there's no Shimano 12 speed cassette for HG freehubs.

 

I did the B-bolt kit upgrade to a GX and it was a good improvement, but I wouldnt throw $30 at an SX or NX, its not worth it.

 

Interesting that it was noticeable on the GX. My GX derailleurs are ok.

My NX derailleur is ridiculously wobbly. This thread reminded me that I wanted to try the B-bolt upgrade, so I found it for 25.99 shipped on ebay from Worldwide Cyclery.

Here is the link in case it is useful to others:

SRAM Xx1 Eagle Rear Derailleur B-bolt and Limit Screw Kit Gold for sale online | eBay

Find many great new & used options and get the best deals for SRAM Xx1 Eagle Rear Derailleur B-bolt and Limit Screw Kit Gold at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

The X01 B-bolt is a worthy upgrade for NX derailleurs, as Mudgard said that's where a lot of slop comes from.

 

I did this change, and it highlighted how much slop was in the parallelogram.

 

How much play in the knuckles? I've had an NX for over a year and can't believe how much play there is.

 

My experience with shift issues in the middle of the cassette are almost always bent hanger or cable sticking.

 

As good as GX and above are, SX and NX derailleurs are garbage. The NX on my son's Status had a similar shifting issue that no adjustment would fix and then the clutch/return spring failed after only 17 miles of use. I would get a GX or higher derailleur and use the NX as a door stop.

EDIT: I replaced his NX with a GX, same hanger, same cable, same shifter, no other changes except mounting and setting up the GX derailleur and it shifts perfect.