Vector 3 and Auto Zero

The topic of the auto-zero feature has come up several times both here and or other forums. The following is a brief summary of how it works, when auto-zero is enabled:

When the Vector pedals are woken up (by turning the cranks), the pedals will try to do an auto-zero. This will succeed if the pedals are stationary for the requisite time (usually less than ten seconds) and the bike is reasonably upright. The pedals will also try to do an auto-zero immediately before going to sleep (four minutes after the last pedaling stroke).
Auto-zero will fail if the bike is not upright, if motion was detected, or if the offset shift is too large (which could be caused by a pedal leaning on something).

Auto-zero can be enabled or disabled from an ANT+ bike computer that has the requisite user interface features and sends the standard control messages.

This does not change any of the manual zero features. You can still do a manual static zero calibration at any time, and you can configure many of the current Edge and Forerunner computers to automatically remind you to calibrate, when they connect to a power meter.

Note that the auto zero will only shift the existing zero offsets a limited amount. Thus, when you install the pedals, you should still do a manual zero calibration at that point to get the pedals into a range where the auto zero will track any further changes.
  • In theory, you could go without ever doing a manual zero offset and then have accurate numbers.

    This is so sweet - big thanks Garmin!

    Though in real life I will most likely end up doing a manual zero offset once a week.

    One question; will the Edge tell if auto zero offset was successful / unsuccessful...?
  • In theory, you could go without ever doing a manual zero offset and then have accurate numbers.

    The offset upon initial installation on a given bike could be sufficiently different from the stored offset, that the auto-zero would reject it. You should always do at least one manual zero after installing the pedals.

    One question; will the Edge tell if auto zero offset was successful / unsuccessful...?

    No, the ANT+ 'calibration pass/fail' message is only sent by a power meter in response to a calibration request by the Edge.

  • Right - on install, a zero offset is a must do. I can see that. And then the auto function should be taking care of the rest.

    BIG thanks for clarifying :-)
  • New to power meters, perhaps being a lot dumb but I cannot calibrate my Vector 3 with Edge 1000 a continued error code 1024. Any ideas ...?
  • 1024 is an error you would get if you were pedaling or otherwise moving the pedals (or leaning on them) during the calibration process. Are you unclipping from the pedals and stationary while doing this process?
  • Since none of this is in the Vector manual:

    1. Is "calibrating" the same thing as "zero offset"?
    2. Is "manual zero offset" the same thing as selecting "Calibrate" from my head unit (Elemnt)?
    3. In Garmin Connect Mobile App, I do not see a "Calibrate" option in the user interface. I only see that on my head unit (Elemnt). Am I missing it somewhere?
    4. If no to 3, why the heck is it not in the mobile app? I rarely use my head unit when riding Zwift in winter.

  • 1. Yes, most Garmin products' power meter user interfaces use "calibrate" to mean "compute zero offset".
    2. Yes. Vector 3 supports the ability to do automatic zero offset determination when first woken up and when it goes to sleep, but will also execute a zero offset determination on command from a head unit.
    3. The GCM app was intended to be a configuration and maintenance tool, not a substitute for a head unit; so it does not implement all of the usual head unit functions.
    4. Ideally, training apps like Zwift would implement the calibration dialog since it's part of the standard ANT+ power meter profile and they are implementing the equivalent to the head unit functionality. As it is, the best alternative if you don't want to use your head unit, is to ensure (through GCM) that auto-zero is turned on; then, if you wake up your pedals a shortly before you set up for your workout, they will do an auto-zero while you get ready.
  • Is the calibration/zero offset written to the pedals, or stored in the software? If I do a zero with my head unit, but I'm also recording with Trainer Road, do I only need to do one zero/calibration?
  • The zero offset is executed by the pedals and stored inside the pedals. You only need to send the zero offset request from one of the devices.
  • The auto zero button is turned off each time I look at the device settings in GC mobile. I turn it on and the unit updates with the “successful” led sequence.

    Next time I look at the device settings, the button is turned off again.

    Is this supposed to be the case, or is something bugging?