Sram eagle GX/NX derailleurs, whats the secret to good shifts?

[DrStupid]

I've been pulling my hair out with the eagle's poor shifting for about a week.

Problems are.
Ghost shifts.
Slow up shift.
Slow down shift.
Over shifts going down the cassette.

The adjustments are good, and about the only thing it does right, is hitting both the upper and lower gears. It always shifts to the big and little cogs, and always shifts off them. This part is fine.

The system has been adjusted by myself, and two mechanics at LBS. The cassette is new PG-1230, the chain is new KMC x12 same length as the old one. The derailleur is new NX. The hanger is straight(* 3).

The chain and the cassette were changed trying to solve the shifting issues. Putting a new cassette on, was the dealers suggestion and was done at no charge. I changed the chain as soon as it started ghosting shifts.

It shifts good on the rack, even perfect. Shifting on the trail it is garbage. I've run the gambit with the B-Srcew, in and out, from the typical setting.

If anybody knows what the magic is, please advise?
I'm beginning to believe the magic comes in a box that says Shimano XT.

 

[Zimmerframe]

I have the sram gx on my Kenevo and I've really really struggled with poor shifts since new. Especially compared to my previous XT 10 speed. I'm constantly adjusting it and it has, to be fair, finally improved over the last couple of weeks. I did use the B screw to wind it in really close, which helped, but then wound it back out a bit .. which actually improved things further.

One of the horses picked the bike up with the gear cable the other day .. which seemed to make things better after I'd re-adjusted it all again.... But that could have been co-incidence or it could have pulled the sheath tight somewhere ?!

I think from other threads where people have described your symptoms, the main theory is that it's most likely caused by where the cable runs. So check that round the handlebars and where it goes into the frame and where it runs when it exits the frame again. It could be that steering and suspension movement are adding and removing tension on the cable, causing ghost shifts and effectively constantly re-adjusting the cable tension.

 

[YrianX]

I was just about to suggest almost the same as Zim... Probably has to do with the cable / housing and possibly routing / moving around?

Has it been this way since new then? Or has it become worse lately? Could be some type of cable grease used reacting to colder temps possibly if it has become worse? Or possibly grit / crud gotten into the housing somehow, though I'm sure you've checked for that...

That said, I haven't owned a GX equipped bike, only tried a few... In my limited experience with them though, the shifts are not as crisp as on X01 / XX1 for sure, though I had no real issues while trying them really...

 

[DrStupid]

I have the sram gx on my Kenevo and I've really really struggled with poor shifts since new. Especially compared to my previous XT 10 speed. I'm constantly adjusting it and it has, to be fair, finally improved over the last couple of weeks. I did use the B screw to wind it in really close, which helped, but then wound it back out a bit .. which actually improved things further.

One of the horses picked the bike up with the gear cable the other day .. which seemed to make things better after I'd re-adjusted it all again.... But that could have been co-incidence or it could have pulled the sheath tight somewhere ?!

I think from other threads where people have described your symptoms, the main theory is that it's most likely caused by where the cable runs. So check that round the handlebars and where it goes into the frame and where it runs when it exits the frame again. It could be that steering and suspension movement are adding and removing tension on the cable, causing ghost shifts and effectively constantly re-adjusting the cable tension.

Thanks!
I will start looking at the cable more closely and in particular at the tension when the suspension moves.

Too funny about the horse. You could write a book zimmerframe... I'm serious

 

[YrianX]

Oh one more thing that had us baffled on a friends bike for a while when it had very variable shift performance and we couldn't figure out why...

Turned out to be the derailleur mounting bolt that was slightly loose, causing a slight bit of flex in the mounting when under load making the adjustment never stay quite right. Shifted fine in the rack and when adjusting, but off on the trail.

 

[DrStupid]

I was just about to suggest almost the same as Zim... Probably has to do with the cable / housing and possibly routing / moving around?

Has it been this way since new then? Or has it become worse lately? Could be some type of cable grease used reacting to colder temps possibly if it has become worse? Or possibly grit / crud gotten into the housing somehow, though I'm sure you've checked for that...

That said, I haven't owned a GX equipped bike, only tried a few... In my limited experience with them though, the shifts are not as crisp as on X01 / XX1 for sure, though I had no real issues while trying them really...

The eagle was good for few months, after initially being finicky to set up. Most the trouble started a week after changing to the NX derailleur. I did pull the cable out, clean, and lightly lube with the shimano cable sauce when changing the derailleur...

 

[steve_sordy]

On my clockwork bikes I've had XO1 Eagle and GX and I've had similar problems. None of my usual fixes would work. And yes, I checked the tightness of the mech-hanger to the frame, and the mech to the hanger. Also, the rear axle, is that at the correct torque and is it thread-locked?

Yes, done all those? Then the very next thing to look at is the mech-hanger alignment. The gaps between the gears on 12 speed are smaller and the derailleur alignment needs to be more precise. I've had all those problems you refer to that only happen under load. The only thing that fixed them was a mech hanger alignment. I had it done twice by the LBS, so I bought myself the alignment gauge/tool and did it myself and took extra time to get it spot on instead of close enough. I had no further problems until the next time I hit my mech on a rock.

The Park Tool one here is excellent! There are cheaper ones, but I can't speak for those.
Park Tool Derailleur Hanger Alignment Gauge DAG2.2 | Chain Reaction Cycles
And here is how to use it:

 

[Rich-EMTB-UK]

Ran Eagle XO1 for years on my none E MTB and zero issues. Just upgraded my TL Expert from SRAM 1*11 which was sketchy to AXS Eagle with NX Cassette and shifting is perfect. Bloody expensive upgrade though

 

[DrStupid]

Thanks all for the help. Replacing the cable with a Shimano optislick did the trick. Wish the NX derailleur had a stronger spring. That cable looked good with no noticeable damage anywhere. I'm just happy to have the old Trance back!

 

[ryturn]

 

[DTZ]

I was never 100% happy with the shifting on my NX mech (came standard on the Base model Levo). After the mech disintegrated on a ride I purchased a replacement, but the only mech the local shop had on the shelf was the pricier GX (I was on holiday in Austria) - after fitting the GX the shifting has been MUCH MUCH better.

After returning from holiday I took my NX to the local Concept store to try and get a warranty replacement (it disintegrated in 2nd or 3rd gear under low load) and they told me that they had a number of failed NX mechs across a variety of bike, all snapped at the same place just under the mech to hanger mounting bolt. SRAM refuse to accept there is an issue and when warranty claims are submitted they just claim bad adjustment and that the mech had been caught up in the spokes (which on mine was a result of the failure, not the cause).

One potential cause of the bad shifting and breakages on the NX mechs is the mech mounting bolt - the machining doesn't seem as good and there may be a little play between the bolt and the bolt hole - possibly only resulting in 0.Xmm of play, but ultimately this movement when exaggerated by the length of the mech could cause bad shifting / failures of the mech due to stresses on that area.

 

[iXi]

My NX broke in the same spot. I was just riding along a fire road and boom top jockey wheel flew out. Bike had only been ridden for 5 months when it died. Got a GX on now and much better, hope it lasts the distance.

 

[YrianX]

Thanks all for the help. Replacing the cable with a Shimano optislick did the trick. Wish the NX derailleur had a stronger spring. That cable looked good with no noticeable damage anywhere. I'm just happy to have the old Trance back!

Great News!

 

[DrStupid]

I was never 100% happy with the shifting on my NX mech (came standard on the Base model Levo). After the mech disintegrated on a ride I purchased a replacement, but the only mech the local shop had on the shelf was the pricier GX (I was on holiday in Austria) - after fitting the GX the shifting has been MUCH MUCH better.

After returning from holiday I took my NX to the local Concept store to try and get a warranty replacement (it disintegrated in 2nd or 3rd gear under low load) and they told me that they had a number of failed NX mechs across a variety of bike, all snapped at the same place just under the mech to hanger mounting bolt. SRAM refuse to accept there is an issue and when warranty claims are submitted they just claim bad adjustment and that the mech had been caught up in the spokes (which on mine was a result of the failure, not the cause).

One potential cause of the bad shifting and breakages on the NX mechs is the mech mounting bolt - the machining doesn't seem as good and there may be a little play between the bolt and the bolt hole - possibly only resulting in 0.Xmm of play, but ultimately this movement when exaggerated by the length of the mech could cause bad shifting / failures of the mech due to stresses on that area.

Thanks for the information. I bought the NX because I was told (or read) it would be more durable! Lol. I didnt realise how good the shimano stuff was until the eagle started laying eggs.

 

[YrianX]

I'll caveat this and my earlier posts with the fact I have not used NX... That said, my personal preference would be the eagle stuff over Shimano for the time being based on my experiences with x01/xx1 vs xt/xtr... to each his own, and personal preference and all that

 

[DrStupid]

I'll caveat this and my earlier posts with the fact I have not used NX... That said, my personal preference would be the eagle stuff over Shimano for the time being based on my experiences with x01/xx1 vs xt/xtr... to each his own, and personal preference and all that

I agree. Mostly I find the Sram stuff frustrating (noisy brakes, finicky shifters, harsh MoCo equipped forks) yet my personal experience with Shimano has been excellent. I didnt spec the bikes that I bought, I just bought. All of my experience is based on 3 recent purchases. I am beginning to understand what I like, and what I dont. If my XT spec'd bike, eats the derailleur tomorrow, and it takes me 3 weeks to make it shift correctly again. I will complaining endlessly about shimano junk. Lol. My wife says that I must Love to bitch, cause I do it so much.