Ever wonder how the StagesBike gets power data from the power meters on the cranks? First, let's identify where all the computers are on the StagesBike:
- R: This is the right power meter.
- L: This is hidden in the picture, but this is the left power meter.
- SB: This is where the StagesBike computer is; it connects to all your apps, allows you to control the flywheel, and connects to the power meters.
Here is how it works:
The right power meter measures the power from your right leg and sends that information to the left power meter. The right power meter only reports right power, so it will always looks like half power when you pair to it on Bluetooth—due to this we do not recommend using Bluetooth.
The left power meter measures the power from your left leg, combines it with the right side's power, and sends that as the total power over ANT and BLE. Any device can pair directly to the left power meter to get LR power, which is what the StagesBike does (via ANT).
The StagesBike pairs to the left meter and passes its data through to connected applications like TrainerRoad and Zwift.
You should really only ever pair to the StagesBike, as it is using the power meter information already.
Pairing to the power meter and stages bike at the same time and using Erg mode can actually cause Erg mode to perform poorly, as an app like TrainerRoad or Zwift and the StagesBike will both try to control to the target wattage.
The "power meter" in the flywheel is an algorithm used for control only and not exposed to the user; the power meters are the primary source of truth, as they measure power directly (most accurate), and the StagesBike adjusts its algorithm according to the error between its math and the power meter's real values.
Everything about the power meters on the StagesBike is "old tech" at this point— it's the same as all the other meters we've been making for almost 10 years and it's proven.
There is no need to zero reset the StagesBike itself, in the Link app when you do a zero reset, it just resets the power meters.
One last thing, with power meter firmware ver. 1.6.8 we introduced an automatic zero reset, so you don't have to do it. It seems, however, we're seeing some cases where this is not great— for example, people leaving their shoes attached to the bike!