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Auto-zero feature on Ant+ Powertap

sergensergen Posts: 39
Does anyone use the auto-zero function on the new Ant+ versions of powertap? 9I'm not talking about the older powertap hubs as they have a very different procedure for zeroing the hub)

the Edge 705 allows you to 'auto-zero' and i know the yellow Powertap CPU also allows you to do this.

To perform this procedure at the start the wheel needs to be stationary. This leads me to the conclusion that possible errors could occur if auto-zero is used becuase the auto-zeroing would also take place at points during the ride where the wheel is stationary - however, torque may be positive, e.g. waiting at a traffic light with the breaks on, but one foot pressing down on the pedals.

Is my understanding of this procedure correct? If so does it not make more sense to avoid use of 'auto-zero' and simply perform a 'manual zero' at the start of each ride.

Posts

  • Auto zero works at it always has, kicking in when coasting, i.e. non zero wheel speed with zero cadence (provided torque is within a certain limit).

    It's manual torque zero that's changed with the Ant+ units, requiring the wheel not to be moving.
  • sergensergen Posts: 39
    Auto zero works at it always has, kicking in when coasting, i.e. non zero wheel speed with zero cadence (provided torque is within a certain limit).

    It's manual torque zero that's changed with the Ant+ units, requiring the wheel not to be moving.

    thanks for the reply Alex.

    Given the above do you know of any reason not to use 'auto-zero'?
  • sergen wrote:
    Auto zero works at it always has, kicking in when coasting, i.e. non zero wheel speed with zero cadence (provided torque is within a certain limit).

    It's manual torque zero that's changed with the Ant+ units, requiring the wheel not to be moving.

    thanks for the reply Alex.

    Given the above do you know of any reason not to use 'auto-zero'?
    if you have a hub that has been converted for fixed gear use then yes you will want to disable the auto zero feature.
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