The Stages Power LR power meter zero reset process is similar to our existing left side power meters. You will position the cranks vertically, with no load on the pedals, and the bike in a stable position, then select calibrate or zero reset from your head unit or Stages Cycling app. Only connect the Stages Cycling app to the left power meter. Since there are two separate power sensors on Stages Power LR, two zero values will be reported. Depending on the head unit used, they may be reported separately as left and right, or shown as two alternating values, with one showing negative (i.e. 890/-890). The zero value range is the same as with our existing meters and should fall within +/- 50 from a value of 890.  

For a more detailed explanation, see How do I calibrate my Stages Power Meter?

Crank position for performing a zero reset.