SRAM rival axs index Q

[Libriform]

Hi there, I recently bought some new wheels for my brand new specialized sl8 expert which runs sram rival axs.

Everything is great except gear 12 (smallest cog) is now rejected (red and green LED flashes) in large ring. All other gears run fine. I notice as well that in the large ring it allows me to be in gear 1 which is cross chain? Is that normal?

Any ideas what I need to do? Is it a limit screw adjustment? I did play with the micro adjustment in the app, and it will go into the smallest cog but still says gear 11 and screws up all the other gears. Firmware all good and it was fine on the original roval c38s.. any advice appreciated

[ReapThaWhirlwind]

It's silly to ask if it's the limit screw without trying that.

I don't have any personal experience with this derailleur, but you'd probably want to go over all the same steps.

You don't have any spacers wrong on the cassette do you?

I've had multiple issues where I thought I needed an extra one when I put it together, because I thought I had slack, but then it messed up the indexing and I was able to remove it without slack.

[meamoantonio]

(01-21-2026, 12:22 AM)Libriform Wrote:  Hi there, I recently bought some new wheels for my brand new specialized sl8 expert which runs sram rival axs.

Everything is great except gear 12 (smallest cog) is now rejected (red and green LED flashes) in large ring. All other gears run fine. I notice as well that in the large ring it allows me to be in gear 1 which is cross chain? Is that normal?

Any ideas what I need to do? Is it a limit screw adjustment? I did play with the micro adjustment in the app, and it will go into the smallest cog but still says gear 11 and screws up all the other gears. Firmware all good and it was fine on the original roval c38s.. any advice appreciated

Hi @Libriform , there should be a shim like tool that comes with your Rival AXS, its meant to help you align your rear derailleur, its a red plastic thing that will help you align the chain gap, I think they came out with a bunch of videos on how to use it let me find it for you

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(01-21-2026, 12:22 AM)Libriform Wrote:  Hi there, I recently bought some new wheels for my brand new specialized sl8 expert which runs sram rival axs.

Everything is great except gear 12 (smallest cog) is now rejected (red and green LED flashes) in large ring. All other gears run fine. I notice as well that in the large ring it allows me to be in gear 1 which is cross chain? Is that normal?

Any ideas what I need to do? Is it a limit screw adjustment? I did play with the micro adjustment in the app, and it will go into the smallest cog but still says gear 11 and screws up all the other gears. Firmware all good and it was fine on the original roval c38s.. any advice appreciated

https://www.youtube.com/watch?v=fO9FuZroc8E

hey @Libriform here you go, it's pretty self explanatory, its pretty hard to describe all of this for me on a thread so I thought using the official video from sram would help out a lot, hope you can fix your problem using this but feel free to post more questions if this doesn't fix it

[JJMarsh]

(01-21-2026, 12:22 AM)Libriform Wrote:  Hi there, I recently bought some new wheels for my brand new specialized sl8 expert which runs sram rival axs.

Everything is great except gear 12 (smallest cog) is now rejected (red and green LED flashes) in large ring. All other gears run fine. I notice as well that in the large ring it allows me to be in gear 1 which is cross chain? Is that normal?

Any ideas what I need to do? Is it a limit screw adjustment? I did play with the micro adjustment in the app, and it will go into the smallest cog but still says gear 11 and screws up all the other gears. Firmware all good and it was fine on the original roval c38s.. any advice appreciated

Make sure the cassette is fully seated on the new wheels. If it's loose, the shifting will be off. Also verify you're using the correct spacer if needed.