1. Switch on your head unit.
2. Turn your crank at least one full revolution – your power meter is now awake
- On current model power meters the LED will flash.
3. Manually zero the power meter using your head unit’s Calibrate command.
- Do this before getting on your bike - there should be no weight on the pedals.
- We recommend putting the drive side crank arm at 6 o’clock.
- On current model power meters the LED will flash again. This takes around four seconds.
- The zero offset – the value returned by the head unit – should be between +/- 1000.
4. If you forget to manually zero the power meter, pedal backwards five times after you begin riding.
- This is the alternative method to zero your power meter and is called Auto Zero.
- You can be on the bike and clipped into your pedals when you pedal backwards.
- On current model power meters the LED will flash. This takes around four seconds.
- When you pedal backward you will not see a zero offset on your head unit.
Zeroing your power meter is the same as taring your kitchen or bathroom scales. Zeroing will ensure you get the most accurate power data. It accounts for mechanical changes – like installing the power meter on a new bike - and substantial changes in temperature and barometric pressure. You can zero the power meter with your head unit’s Calibrate command (Manual Zero) or by pedaling backward five times (Auto Zero).
- The zero offset should be between +1000 and -1000.
- Ride to ride and day-to-day variation should be less than 50 points.
- Values >1000 and <1500 are okay if the variation is <50
- Values >1500 require examination
With a new power meter or newly installed chainrings, the zero offset may take 2-3 rides to stabilize. During this time you should zero regularly to ensure accurate power readings. The zero offset has stabilized when it moves by less than 50 points. Short, hard efforts in both chainrings on your first ride will speed up stabilization.
When you zero, the LED provides useful information about the condition of the power meter. The LED will flash:
- Once if the power meter is paired with a head unit.
- Twice if not paired with a head unit.
- Three or four times if power measurement components have failed.
Periodic cleaning is recommended. Use a rag to wipe debris from the power meter, crank arms, magnet and chainrings. Brush the power meter, crank arms, magnet and chainrings with clean or soapy water, then rinse with clean water and air dry. You should not use harsh chemicals or a high-pressure washer to clean your power meter.