Strava Power Calculations
 

I know this is estimated power, but I'm curious why nearly all of my rides show nearly 0-watts for the first half of the ride.

I read somewhere that it's really only decent during a climb, which would appear to be accurate since that's when the power came off the peg. However, on the 'downhill' it continued to estimate power output. Anyone else see this with their rides or make any sense of it?

(Ignore the fact that my 'climb' is pretty much nothing.)

http://www.ancker.net/embed/screen1.png

I think there's some sort of factor dependent upon the phase of the moon along with something to do with chicken bones.

Clearly you weren't pedaling for the first 18 miles. Seriously, get a power meter if you want power numbers. GL

Algorithms are NO MATCH for strain gauges. I do have an Elite SuperChrono trainer with a head unit, which supposedly gives a power read out...but It's wrong. Very wrong. Although consistent within itself.
That's the advantage of an algorithm based system..it's accuracy will not drift. 200w on the trainer today is the same as it is tomorrow.
It's O.K. Gets me by.