Mike Prevost wrote:
Exactly my point. On a bike, power to go a specific speed varies with wind direction. Same with this system. This is exactly what you want. It IGNORES wind, just like a bike power meter and measures only the power you are producing. It does not have to account for wind and should not. On a bike, you have speed and power. On this device you have pace and power. That is all you need. In other words, this system is estimating power by measuring acceleration. The estimate of power is dependent of wind, as it should be.
Absolutely and provably not true.
On a bike, the power you expend is:
P = CdA * 0.5 * rho * w^2 * v + m*( a + Crr*g)*v + m*g*s*v ,
where
w is airspeed
v is ground speed
s is slope
How does measuring only "a", "v", and "s" give you the total power, P? What kind of sorcery is this? :-)
Quote:
Using your example, run a 6:00 pace into a head wind VS tail wind and you will have to produce a higher acceleration into the wind, which presumably this device will measure, therefore more watts. Just like a bike pwoermeter. Wind does not matter for measurement purposes.
No, that's not the way physics works.
Newton's Second Law of Motion states that:
m*a = sum of forces on a body
So acceleration is 1/m times the net sum of forces on a body. Acceleration is the result of net power application. Not the cause of it.
AndyF
bike geek