Skip to main content

How to Zero Your Power Meter

When it comes to power meters, a cyclists’ first concern is always accuracy – and rightly so. After all, what’s the point of measuring power if the data isn’t accurate? However, most of what makes a power meter accurate is outside of our control. How it was designed, engineered and assembled all contribute to a power meter’s accuracy. There’s not much we can do as cyclists to ensure accuracy in this regard, other than make sure we’re buying a power meter from a name we trust. However, there is one thing every cyclist can do to aid in the accuracy of their power meter. It’s easy and only takes a few seconds. Perform regular zero-offsets. Depending on the power meter, they should be performed before every ride. This article aims to address what zero-offsetting is, why it’s important and how to zero your power meter depending on which one you have.

how to zero your power meter

 

How to Zero Your Power Meter

Calibration and Zero-Offset

We want to take a moment to remind everyone that the terms calibration and zero-offset are often used interchangeably, when in fact they refer to two separate, distinct procedures.

Calibration refers to a one-time procedure the manufacturer performs when your power meter is assembled. Specifically, the manufacturer sets the ‘slope’ of your power meter. Your power meter uses the slope to determine the correct wattage output when you ride.

Zero-offsetting or zeroing, is a procedure that is performed before every ride. When you do a zero-offset, the power meter zeros out any residual torque that has built up in the power meter from previous rides, temperature changes or installations. In essence, zeroing wipes the power meter clean. Think of zeroing as setting the tare on a scale. You wouldn’t step on a scale if it was reading 10 lbs. with nothing on it – nor should you just hop on your bike and ride without performing a quick zero-offset.

 

General Zero Procedures

While the steps taken to zero each power meter vary slightly, the general process is the same – and it’s quite simple.

  1. When you perform a zero, you should be off of the bike. The pedals should be completely unweighted
  2. On your bicycle computer, navigate to the calibration page and select Calibrate. (Again, you’re really zero-offsetting but most bicycle computers erroneously call it Calibrate)
  3. You should see a “Calibration Successful” message (on most systems anyway, again refer to your power meter below for exact steps)

Also, here are two helpful tips to keep in mind:

  1. It’s good practice to be sure you have the latest version of software installed on your head unit. This can help avoid issues during the calibration process
  2. If you have any ANT+ compatible devices paired with your head unit that aren’t currently in use (heart rate monitor that you are not currently wearing, speed/cadence sensor that is not currently on the bike, etc.), we recommend that you disable them on your head unit. Sometimes, the head unit will continue to search for these before proceeding to the calibration procedure

 

How to Zero Your Power Meter Based on the Manufacturer

Image of the 4iiii Innovations logo

4iiii

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Align the crank arms vertically with the left arm in the 6 o’clock position and right arm in the 12 o’clock position
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should see the two digit code “10” and a “Calibration Successful” message
Image of Assioma logo

Assioma

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Align the crank arms vertically (at 6 and 12 o’clock)
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful 0” (It’s important the value is 0. If not, repeat the calibration procedure again)
bepro-logo-1024x505-2-1024x556

bePRO

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. You should see 3 blinking lights on the pedals
  3. Align the crank arms vertically (at 6 and 12 o’clock)
  4. On your bicycle computer, navigate to the calibration page and select Calibrate
  5. You should receive a message saying “Calibration Successful 0” (It’s important the value is 0. If not, repeat the calibration procedure again)

bePRO also recommends you perform a dynamic calibration procedure after each new installation. It can also be performed from time to time to ensure maximum accuracy. The dynamic calibration checks the alignment of the pedals (sets the installation angles).

Steps:

  1. Put your bike on a trainer (not mandatory but makes things easier)
  2. Get on the bike and select a gear that allows you to maintain a cadence of around 80 rpm
  3. Cycle backwards 10-12 times at a cadence of around 60 rpm (this tells the pedals you are about to perform a dynamic calibration procedure)
  4. Start pedaling normally
  5. Try to maintain a constant cadence of around 80 rpm for at least 40 seconds
  6. During this time, power will read 0 watts
  7. Once the procedure is complete (around 40 seconds), you will see power data start to show again on the head unit. Once power starts to show, the procedure is complete
Easton Race Face company logos

Easton | Race Face

When:

It is not necessary to perform a zero-offset before every ride, however it is recommended to zero-offset the power meter periodically in order to ensure maximum accuracy. In addition, a zero-offset is recommended after changes to the crank such as changing pedals, chainrings, installation of the crank, tightening of bolts, etc.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Align the crank arms vertically with the non-drive side crank arm at 6 o’clock (pointing down)
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful”
Image of the FSA logo

FSA

When:

Never.

The PowerBox has Auto Zero, a feature that performs an automatic zero-offset every time you coast for at least two seconds during a ride. Therefore, while it is still possible to perform a zero using the head unit, it really is not necessary. Just get on your bike and ride, the PowerBox will do the rest!

Image of the Garmin logo

Garmin

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Position the cranks in a horizontal position (3 and 9 o’clock)
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful”
Image of the Velocomp PowerPod logo

PowerPod

When:

The first time you ride outdoors only.

Steps:

  1. With the light on the PowerPod yellow, press the button on the top of the PowerPod
  2. You now perform a 5-minute ride during which point the PowerPod will calibrate. Ideally, aim for a steady ride with minimal stops or interruptions
  3. During the ride, the light will flash yellow, indicating that the calibration procedure is in progress. You will also see the watts on your head unit increase from 1 to 100. (The number indicates the % complete. So at 50 for example, your head unit is saying the calibration procedure is 50% complete.)
  4. After 5 minutes, you should reach 100, at which point the calibration process is complete and your actual power will begin to show
  5. Click the button on the PowerPod again
  6. The light should flash green
  7. Begin pedaling and the light should turn solid green
Image of the PowerTap logo

PowerTap P1 and P1S Pedals

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. On your bicycle computer, navigate to the calibration page and select Calibrate
  3. You should receive a message saying “Calibration Successful”. The head unit might also include a number in the calibration successful message like 5 or 20. This number refers to the zero offset value and isn’t something you need to worry much about
Image of the PowerTap logo

PowerTap G3 Hub

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the hub
  2. On your bicycle computer, navigate to the calibration page and select Calibrate
  3. You should receive a message saying “Calibration Successful”
  4. Note that the G3 Hub will self auto-zero while coasting – which will help keep it calibrated at all times
Image of the PowerTap logo

PowerTap C1 Chainring

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. On your bicycle computer, navigate to the calibration page and select Calibrate
  3. You should receive a message saying “Calibration Successful”
  4. Note that the C1 Chainring will self auto-zero while coasting – which will help keep it calibrated at all times
  5. Also, some users have noticed that the accuracy is a bit off for the first ride or two while the bolts and fasteners settle in a bit. This isn’t anything to be concerned about, rather just something to be aware of. After a few rides you should be good to go
rotor-logo-positive

ROTOR 2INpower/INpower

When:

The 2INpower and INpower does not need to be zero’d before every ride, but rather after the initial installation or after changing any drivetrain componentry (pedals, chainrings, etc.). It is also recommended that you perform a second zero-offset after 30 hours of riding.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter. (Note that with some head units, you do need to apply a load to the crank and pedal a few times before entering the calibration menu)
  2. Align the crank arms vertically with the left arm in the 6 o’clock position and right arm in the 12 o’clock position
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful 1000”
  5. Slowly turn the crank counterclockwise two or three turns and align the crank arms vertically again with the left arm in the 6 o’clock position and right arm in the 12 o’clock position
  6. Calibrate once again and record the offset value shown
  7. You can repeat the process if necessary to ensure numbers are in the same range (+/-200)
Image of the SRM logo

SRM

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. On your bicycle computer, navigate to the calibration page and press Set
  3. The screen displays the current zero-offset and the previously stored zero-offset
  4. Once the current zero-offset value remains stable for a few seconds, press Set again
  5. You have set the zero-offset and both numbers should now have the same value
Image of the Stages Cycling logo

Stages Cycling

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Align the crank arms vertically with the left arm in the 6 o’clock position and right arm in the 12 o’clock position
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful”

You can also preform a zero-offset using the StagesPower app on your mobile device

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Align the crank arms vertically with the left arm in the 6 o’clock position and right arm in the 12 o’clock position
  3. Open up the StagesPower app on your mobile device and select “Connect via Bluetooth” on the iOS app or select the power meter from the list of Discoverable devices on the Android App
  4. Select “Zero Reset” from the app. A zero reset value will appear under “ADC” once the process is complete
Image of the Verve Cycling logo

Verve InfoCrank

When:

Never.

The InfoCrank does not need to be zero’d. As you’ve already learned, the reason for zeroing a power meter is to zero or cancel out any residual torque that has built up in the power meter from previous rides, temperature changes or installations. The InfoCrank was constructed and designed in a manner in which residual torque never accumulates in the power meter. The InfoCrank reads true and accurate 100% of the time – no zeroing necessary. It is a ‘get on and go’ power meter.

Note that in the event of a major crash which directly impacts the InfoCrank, you can choose to perform a zero-offset procedure if you wish.

Steps:

  1. Align the crank arms vertically (at 6 and 12 o’clock)
  2. Place the chain on the smallest chainring
  3. On your bicycle computer, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful 0”
  5. Repeat the process as necessary until the calibration reading goes to 0
Image of the WATTEAM logo

WATTEAM

When:

Before every ride.

Steps:

  1. Spin the cranks backwards a few times to wake up the power meter
  2. Align the crank arms vertically with the left arm in the 6 o’clock position and right arm in the 12 o’clock position
  3. On your bicycle computer or smart phone, navigate to the calibration page and select Calibrate
  4. You should receive a message saying “Calibration Successful”
admin

Related News

Power Meter Tips and Tricks

This is an ongoing article where we will be compiling some cool power meter tips...

Power Meter Calibration vs. Zero-Offset

The terms power meter calibration and zero-offset often get used interchangeably. However in reality, they...

Banner image for our Set Crank Arm Length for Power Meter Pedals article

Set Crank Arm Length for Power Meter Pedals

Set Crank Arm Length for Power Meter Pedals When using meter pedals, your bicycle computer...

Shopping Cart