jmjtri wrote:
Pantelones wrote:
jmjtri wrote:
Bdaghisallo wrote:
jmjtri wrote:
To be fair, Bike power meters don't measure power either. They calculate it . Most bike power meters measure strain, then calculate force and then work and then power.They don't measure it directly, but they do measure the inputs of the power=force x velocity equation directly. C2 seems to track metrics that infer those inputs with assumptions thrown in to get them there.
Force isn't measured from the power meter. It is calculated from the recorded strain of the crank. These assumptions that you're talking about aren't assumptions. They're variables. You can calculate power based on acceleration of a free wheel too. As long as the mass and rotational inertia of the wheel are known it will be accurate.
Actually most PMs doesn't record the strain, they measure the resistance change for a metallic foil pattern as the pattern deforms on the body of observation. Strain/Stress is inferred from the resistance change.
Who wants to be the next pedant to correct me?
You're literally describing a strain gauge.
That is because most powermeters literally use strain gauges.