power meter question

[berty bassett]

hi - may be stupid question but as I was trundling along this morning watching numbers , I was puzzled a bit by the readings , am I right in thinking that if you are riding with a power meter up a hill you have rode many times and you want to beat your pb , power meter readings don't mean a lot without taking cadenced speed into account ? if I was going up said hill at say 4w/kg in a lower gear @ 90rpm,, I could be going slower in a harder gear at say 5w/kg @ 55rpm so all of a sudden , power meter reading alone aint worth anything without taking other readings as well ? - maybe total flannel but just what was going thru mind today - anyone able to confirm theory or willing to put me right

 

[Ming the Merciless]

Total flannel

Power = cadence x torque. Already accounts for cadence.

 

[presta]

Ming is right, power at the crank is the product of torque and angular velocity, but the efficiency of your body depends on torque and cadence - that's why we have gears in the first place. Your heart rate monitor will tell you your optimum cadence: just pick the gear which gives you the lowest HR for a given speed, or conversely, the highest speed for a given HR. Note that optimum cadence is proportional to your power output, so what's optimum at one power/speed/gradient etc won't necessarily be optimum for another.