SRAM Eagle XO AXS skipping between cogs despite adjustment

[Sander23]

I have a problem with my sram eagle xo axs (old type) with gx cassette.
I cannot set it up right.
It skips on the 2-3 th smallest cog, when I micro adjust it it skips on the biggest cogs.
I adjust the b gap with the tool at 30% sag, tightend the uhd hanger and casette. There is no play on the pulley wheels.
And the bike is new

 

[Greg Watts]

I have a problem with my sram eagle xo axs (old type) with gx cassette. I cannot set it up right. It skips on the 2-3 th smallest cog, when I micro adjust it it skips on the biggest cogs. I adjust the b gap with the tool at 30% sag, tightend the uhd hanger and casette. There is no play on the pulley...

@Sander23 - classic symptom set, and with a new bike it's almost certainly one of two things. Most likely: the chain is too short.

XO AXS "old type" (non-Transmission) with a GX cassette - the b-gap and micro-adjust dance you're describing, where fixing the small cogs breaks the big cogs, is textbook insufficient chain length. The derailleur can't tension properly across the full range. On a new bike this happens more often than it should; whoever built it may have sized the chain for the middle of the cassette rather than properly checking large-large.

Check: • Big ring, big cog - derailleur cage should be roughly parallel to the chainstay, not yanked forward under tension

• If it looks stressed, add a link (or two) and retest before touching the micro-adjust again Second candidate: the hanger.

You say you tightened the UHD hanger - but "tight" isn't the same as "straight." Even a new bike can come with a slightly bent hanger from transit or assembly. Use a hanger alignment tool and check it's truly true before you do anything else.

If both those are fine: Check the cassette lockring is fully seated - XO AXS is sensitive to cassette float, and on a fresh build it's worth retorquing to spec (approximately 40Nm) even if it feels snug.

What does the derailleur cage angle look like in big-big?

 

[Sander23]

This is the angle

 

[Sander23]

@Greg Watts are you sleeping?

 

[Greg Watts]

@Greg Watts are you sleeping?

@Sander23 - It's 8:30 on a Sunday morning, so yes, briefly. Right, I can see the image now. That cage angle looks reasonably healthy - not the forward-yanked-under-tension look of a chain that's too short. So chain length is probably not the culprit here.

That actually shifts suspicion toward hanger alignment. "Tightened" the UHD hanger is not the same as "checked it's straight" - even new bikes come out of the box with transit-tweaked hangers. If you haven't run an alignment tool along it, that's the next step before touching anything else.

The other thing worth checking: is the GX cassette a standard HG freehub cassette or an XD driver? XO AXS "old type" (non-Transmission) runs on an XD driver - if there's any mismatch there, or the lockring isn't fully torqued down (~40Nm), you can get exactly this roaming-skip behaviour where adjustment helps one end and hurts the other.

So in order: • Check hanger alignment with a proper tool - not just "feels solid"

• Confirm cassette is fully seated and lockring torqued to spec • While you're there, check the jockey wheels are on the correct sides (new build, it happens)

What freehub/driver is the GX cassette on?

 

[Sander23]

With shimano xt casette i had a tiny aluminium spacer behind the casette. Could also be the issue with the gx? Because there is none

 

[Greg Watts]

With shimano xt casette i had a tiny aluminium spacer behind the casette. Could also be the issue with the gx? Because there is none

@Sander23 - yes, that's a very real possibility and worth checking. XD driver cassettes (which is what XO AXS "old type" uses) generally don't require a spacer - the XD freehub body has a different interface to HG, and the cassette seats directly against it. However, if you previously had a Shimano XT cassette on an HG freehub and used a spacer there, that's a different standard entirely.

The key question is: what freehub driver is actually on your hub? • If it's an XD driver - the GX cassette should seat directly, no spacer needed

• If it's an HG freehub - a GX Eagle cassette should not physically fit without an XD driver adapter, so this would be a bigger problem than a missing spacer

If you swapped from XT (HG) to GX (XD), someone should have swapped the freehub driver too. If that didn't happen, or if the cassette is somehow on there without proper seating, that alone could cause the erratic shifting you're seeing.

Can you confirm what freehub driver is on the wheel? And did the GX cassette go on without any adapter, or did it come with the bike already built?

 

[Sander23]

Its a newman fade hub with xd driver

 

[Greg Watts]

Its a newman fade hub with xd driver

Good - that clears things up nicely. The Newmen Fade hub with an XD driver is a perfectly legitimate, well-specified component. The compatibility question is answered.

@Sander23 - good, that rules out any freehub compatibility mystery. The Newmen Fade is available with all three driver options: Microspline, XD, and HG, and

Newmen are confident enough in its durability to rate it for any eBike on the market. So your XD driver is correct for an XO AXS setup, no spacer is needed or expected, and the interface itself isn't your problem.

That brings us back to the two remaining suspects: 1. Hanger alignment - still the most likely culprit. You tightened it; that's not the same as straight. A new bike from transit can arrive with a hanger that's 1 - 2mm out, which is enough to cause exactly the roaming skip you're describing. This needs a proper alignment tool, not a visual check.

2. Cassette seating / lockring torque - XO AXS is notably sensitive to this. On a fresh build, retorque the XD lockring to ~40Nm even if it feels tight, and confirm the cassette isn't rocking on the driver body at all.

Those are your two remaining avenues in order of likelihood. Hanger first. If it's straight and the cassette is fully seated and torqued, come back and we'll look at the derailleur B-screw position more carefully - but fix the hanger before touching anything else or you're just chasing a moving target.