SRAM NX 12 Speed Shifting Issues

Anyone able to help?

I have a SRAM Eagle NX 12 speed on my bike. It has only done about 40 miles but it doesn’t seem to want to downshift. It like there is too much friction in the cable to release it or the spring isn’t strong enough to pull it back down.

The bike is due back at the LBS for a 6 week service so can hopefully get it sorted then but got a couple more rides this week before it goes in.

have tried adjusting the cable and indexing but that doesn’t seem to be the issue

My guess would be the b-screw setting, or the chain is slightly too long… or maybe both! SRAM 1x seems to behave better with the top jockey wheel nearer the cassette (I think they recommend about 10mm)

Cheers will have a look at that then.

Oops, I was going to suggest exactly the opposite!

My GX setup has been endlessly fussy and still isn’t great, but it was a lot worse when I fitted a 2 tooth bigger chainring without increasing the chain length. Back to the smaller chainring and the shifting is (mostly…) OK.

With the bigger chainring it did the same as yours i.e. got ‘stuck’ in the lowest gear/biggest cog.

Almost certainly the “B” screw adjustment. Jockey wheel needs moving closer to the cassette. There is a plastic tool that comes with it that is used to set the gap. If it is an FS bike you must do it with the suspension in the sagged position as the gap changes. Mine was doing the same thing, the gap was correct static but was too big when sagged. It needs to be spot on to work properly and not “near enough” as it was in the old days.

With the bigger chainring it did the same as yours i.e. got ‘stuck’ in the lowest gear/biggest cog.

It would because the bigger chain ring(in effect a shorter chain) would cause the jockey wheel to move away from the cassette very slightly.

When I was in a workshop we had a loads of Sram shifters come back which had stopped down shifting. What happens is when the rear mech is at full extension and you shift down, the cable comes loose in the shifter. As the inner junk rotates it folds the end over and it gets jammed up.

Might not be your problem but worth being aware of for Sram users.

Well I managed to get it sort of functioning last night prior to my ride with some adjustments, but lost all 12 speeds. Would shift into the top ring but think I can solve that when I am not trying to do it turned upside down in a trail car park!

lots of NX rear mech issues seen in the shop. the pivots have play from new and bind when coming back down the cassette. have warranted a couple & replaced with GX on a few. apex mech seem to be suffering similar issues too

To be honest I have been completely unimpressed with my GX. Looks like I have trashed another mech following my chain snapping a couple of weeks back. Can’t get it to index at all. Tried everything. I have ordered a new X01 mech now, after being assured they are much stronger than GX. Personally I’m now in the departure lounge awaiting Shimano XT 12 speed. Hell I may even go XTR if I’m feeling flush.

Cheers RD. Sounds similar – I am surprised at how much play there is in the rear mech. Seems quite loose.

Have got it vaguely working which will allow me to ride on Saturday before it goes back to the shop next week.

Rear hub sounds very rough as well so think that will need replacement.

I thought they would of sorted that play out by now,I bought an 11 speed one when they first came out .It didn’t make it out of the shop because I noticed a lot of side to side play in the main axle and couldn’t work out how that would ever be a good thing setting up the gears with some consistency.Then the replacements the shop ordered in weren’t much better so went for a GX again .

Personally I’m now in the departure lounge awaiting Shimano XT 12 speed. Hell I may even go XTR if I’m feeling flush.

Yep, I’m also eyeing up SLX 11spd for mine, GX has cost me too much in replacement jockey wheels and cables, and still only shifts ‘just about OK’.

Edit: although I will take a look at that B-tension again…

following.

im not sold on gx eagle at all.

although people keep telling me off for block shifting (3 gears into the big ring)

I’ve just bought xtr 12 speed rear mech and shifter to replace gx eagle. Even with the new style cage and jockey wheels it jammed solid and bent the mech for no reason that I could see apart from a tiny bit of mud.Thats the 2nd trashed mech in 6 months. Ideally I would have waited for xt 12 speed but didn’t want to spend any more cash on sram. I think xtr mech and shifter with gx cassette, chain and chainring will be a good combination.