Power-speed question
I have always thought that given wind, weight, etc., power determines speed. But I was fooling around in a group ride today and noticed that going a steady speed (behind some guy), shifting between gears altered the power (and yes I did let the power meter settle down). I believe it was the case that easier gears (and thus higher cadence) led to higher power. Again, that's maintaining the same speed.
Physics nerds, what gives?
And if I'm right (and I saw it with my own eyes), is it possible to overvalue power?