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Bug with Sram etap 11s after firmware upgrade to 21.17

stepolin
5 months ago

After firmware upgrade, there are several errors in the 840 - Sram etap 11s communication:

- incorrect reading of the gearings, continuosly alternating e.g. 50 - 34

- annoying beep every about 10 seconds

- the rear derailleaur stop to work (!). I cannot confirm it is because of the upgrade, but it happened two times, the second one after deleting the sensor and repeating the pairing.

I had to disable the sensor, otherwise it is impossible to ride with the continuous beeps of the Edge

Is it possible to downgrade the firmware?

SP

  • 0 4 months ago in reply to aweatherall

    In my experience, I had the Edge 840 and the SRAM RED-RD-E-A2 working correctly, before the upgrade to firmware version 21.17

    So, whatever the problem is with the ANT+ protocol, the previous firmware version (21.16?) was handling it correctly.

    If it is possible to downgrade the firmware, I'm pretty sure it will work again. Anyone at Garmin could provide me with the old firmware?

  • 0 4 months ago in reply to stepolin

    The issue is that the ANT+ Spec changed to include button and trim support for SRAM and other companies using the ANT+ Spec. The Edge update included those new features, not all AXS systems appear to have been correctly updated to handle the additional information requests that the spec now supports.

    So, yes the Edge changed, but the fix is needed on the AXS side as it is now no longer correctly handles the latest version of the ANT+ spec.

  • 0 4 months ago in reply to aweatherall

    I don't have the AXS 12 Speed system, but the revised version (A2) of the first etap 11 Speed derailleur (A1). The new A2 rear derailleur is totally compatible with the old front derailleur and shifters, which I didn't change. It does not have any of the new features of the AXS system.

  • 0 4 months ago in reply to stepolin

    Understood. The issue is how the system is coded to handle requests it does not know about. 

  • 0 4 months ago in reply to aweatherall

    Changing specification so that it breaks existing implementations does not sound promising for the future.

  • 0 4 months ago in reply to macnuts

    The existing parts of the spec were not changed, additional functions (message types) were added. The issue is how products that do not support the full range of a spec handle the bits they don't support. The requirement for how products handle that did not change. It just appears that until the new functions were added the system support all the required calls, so the handling of unsupported message types was not exposed.

    Both Garmin and SRAM are aware of the issue so I expect it to get resolved fairly quickly. 

  • 0 4 months ago in reply to aweatherall

    So, in my case, the old firmware was working correctly, before this update:

    Changes made from version 20.19 to 21.16:

    • Added support for button control and trim adjustments for SRAM AXS shifting systems

    which introduced message types not handled by my etap (non AXS) derailleur.

    Considering that the first etap RD (A1) never received a firmware update - and I'm expecting the same for its A2 replacement - I definitely need to revert my 840's fw back to version 20.19.

    If downgrade is not possible, what about a factory reset? Will it revert back to the original firmware of the device, at the time I bought it?

  • 0 4 months ago in reply to stepolin

    I'm guessing that Garmin will need to code around the issue as SRAM will not want to push out a software update for the eTap.

    I have the A1 and it works without issues, so it appears to be specific to the A2.

    You need to roll back to 20.19 until a software fix is available.

  • 0 4 months ago in reply to aweatherall

    I would do the downgrade, only I find no instructions how to do it.

    Do you know how to do it?

  • 0 4 months ago

    I am facing issues with the SRAM Quark Powermeter since I have 21.18 installed. Every here and then it "drops" the power value and displays a 0. This was not happening with the former Firmware (no idea if this was 21.17 or something else)

    Checked this with an Assioma Powermeter and did not run into that issue. 

    Its annoying ....