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Discussion Starter · #1 ·
Hello all, got a question and wondering what your thoughts are on the matter. I purchased an AXS Eagle derailleur and shifter brand new back in May (4 months ago). They have been working flawlessly as all the glowing reviews indicate they should.

This past week, I started having gear trouble in the mid-range of my cassette, specifically gears 6 and 7. The chain jumps around and will not hold the desired gear. To troubleshoot, I first adjusted my derailleur (b tension, limits, micro adjustments). The problem persisted. Next I installed a brand new hanger on my bike. The problem persisted. Next I installed a brand new chain, cut to proper length. The problem persisted. Next I installed a spare Eagle cassette I borrowed from a friend. The problem persisted.

I was stumped. But then I took a very close look at my derailleur behavior. When I shift all the way down to my smallest cog on the cassette (10t), and then try to shift up to the next largest, the derailleur shows a green light, but only makes a soft “bzz”noise followed by light clicking and does not actually move. But if I go into third or any other gear, it makes a loud “BZZ” and shifts properly. The issue is going into the second smallest gear, it simply won’t move and introduces shifting problems in the middle of my cassette range as the derauiller tries to catch up to where it actually should be.

Has anyone else experienced something similar? After hours of investigating I plan to visit the bike shop to get their opinion.
 

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At first I was thinking it could be the hanger but reading further, I'm not sure.

It could be that the rear mech has problems, you can contact SRAM and get their input. If you can, capture some video and post it here.
 

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Discussion Starter · #3 ·
At first I was thinking it could be the hanger but reading further, I'm not sure.

It could be that the rear mech has problems, you can contact SRAM and get their input. If you can, capture some video and post it here.
I've dropped it off at the bike shop, they mentioned perhaps the battery isn't supplying enough juice to the derailleur, even though the light is green and it shifts well for 11/12 gears... simply won't budge for the first gear as it tries to transition from the 10t. Will update this thread as I learn more!
 

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Have you tried thoroughly soaking all the rear derailleur parallelogram pivots in penetrating oil to make sure they're fully lubricated and moving smoothly?

You mentioned how it's struggling to move and then is doing a delayed shift. That sounds like it could possibly be this issue which is a mechanical one where the parallelogram pivots corrode and stick:

 

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Discussion Starter · #7 ·
I thought it was the pivots too, but wanted a second opinion before starting to fiddle with it too much.

Bike shop agrees that it’s something with the servo motor. More specifically the micro-adjust. They claim that they try to adjust the indexing in the stand and it won’t move or has delayed movement. I’ve noticed it “clicking” in the stand when I’m not even pressing a button. Something is certainly off. They charged up my battery and said it was nearly full when it came in, was only only the charger briefly before it topped off.

Old AXS is being sent off for warranty. New AXS installed, drivetrain runs and shifts perfectly as it should.

Hopefully this thread proves helpful to others who might have the issue, though it seems uncommon for these high end mechs.
 

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Sorry a bit late to the party and lowly your problem is solved but it sounds like a gear in the stepper motor gearbox is broken. This can happen if the bike is dropped on the derailleur when the battery is not connected. For the derailleur save feature to work the derailleur needs power. So when the bike is stored make sure it is secure and cannot fall and that the derailleur cannot be bumped with force like by your teenager parking the car in the garage and your bike happens to be between it and the wall…
 

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Discussion Starter · #9 ·
Sorry a bit late to the party and lowly your problem is solved but it sounds like a gear in the stepper motor gearbox is broken. This can happen if the bike is dropped on the derailleur when the battery is not connected. For the derailleur save feature to work the derailleur needs power. So when the bike is stored make sure it is secure and cannot fall and that the derailleur cannot be bumped with force like by your teenager parking the car in the garage and your bike happens to be between it and the wall…
Thanks for the response, one year later from my original post and my warrantied AXS is working without a single issue. Very interesting about the "derailleur save" function. I keep my bike in the garage with the battery in, but will remove it on long trips when loaded on a bike rack to save battery life. Is there any way to reset to "derailleur save" function if it gets bumped without the battery in?
 

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Thanks for the response, one year later from my original post and my warrantied AXS is working without a single issue. Very interesting about the "derailleur save" function. I keep my bike in the garage with the battery in, but will remove it on long trips when loaded on a bike rack to save battery life. Is there any way to reset to "derailleur save" function if it gets bumped without the battery in?
I haven't disassembled an AXS derailleur yet to determine exactly how the overload clutch works and there are several ways I can envisage it working The simplest is with a spring that pulls or pushes the drive motor shaft into the gearbox but from what I see with the units I've installed is that it's an accelerometer in the electronics that detects a high lateral acceleration and uses the motor to get the derailleur out of the way. It seems to only work when powered up and theres a brief whizzz whizzz when it takes a load. So if unpowered, it is possible to break a gear tooth in the gearbox in much the same way as one could break a gearbox of an RC car steering or RC plane aileron or elevator servo. In terms of reset, this will happen when you power it up. The position sensors built into the derailleur with adjust it back to where it was. This won't be a massive movement
 
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