Benefits of Using the Scale Factor Setting for Garmin Power Meter Pedals

Users can input a scale factor for the left and/or right pedal for a Rally or Vector Power Meter system. The Scale Factor is stored in the pedal and adjusts the power value that is calculated on the pedal and transmitted to and stored on the paired head unit such as an Edge cycling computer.

Why Would I Use the Scale Factor Setting?

Adjust for Power Drift From the Original Factory Calibration

Garmin does not expect the factory calibration of Vector pedals to drift, but we have put this capability in place for advanced users that want to test and adjust their Vector pedal settings as required. if, after repeated static torque tests, the reported torque value is different from the expected torque value, you can adjust the factory calibration with a scale factor input for one or both pedals

Adjust the Reported Total Power of a Vector S System for a Cyclist With a Known Left-Right Imbalance

We know from our research that a cyclist’s left-right power balance is dynamic and changes with power, cadence, and riding style, but we have put this capability in place for advanced Vector S users who want to adjust for an imbalance. For example, if a cyclist knows that he is consistently 47%-53% in his left-right power output, and wants to scale his power reading to more accurately reflect his total power, he could scale (i.e., uplift) the left power in his Vector S pedal to account for this bias.

• To calculate the scale factor, use the assumed left leg contribution % in the following formula: (100/L%)/2. In this example, (100/47)/2 = 1.0638

• Enter this value (1.0638) as the left pedal scale factor

Accommodate a Bike Setup Where the Crank Arms Have Different Lengths

If a cyclist had a 170.0 mm crank on the left, and a 172.5 mm crank on the right, he would set the crank length to 170.0 mm on the head unit. With this crank length setting, the left side pedal would be reporting the correct power values, while the right side would be under-reporting power

• To correct the right side value, you will need to uplift it by the following ratio: 172.5/170 = 1.0147

• Enter this value (1.0147) as the right pedal scale factor system to uplift its reported power. Leave the left pedal scale factor unchanged at 1.0000

Where Are the Adjustment Settings Located?

The settings can be found within the sensor details from a paired Edge cycling computer.  Below is an example from an Edge 1030 Plus with a pair or Rally pedals connected to the head unit.  Your settings may vary.  Refer to your owner's manual on how to access the sensor settings on your device.