Polar Power Sensor Installation

I have just installed a power sensor, cadence and speed.



My bike is a DeRosa King so the mount was a bit difficult do to the chain
stay curvature.



Power sensor needs to be tilted about 30 degrees downward (on outboard side)
so that cadence can be picked up and very little rubber used so that chain
will not rub top of sensor.



After riding 700 miles this way all seems to work OK except it is saying
that I am heavily right leg dominant in my pedaling power.



Is this true or is it something about an improper installation?



What does a proper installation really look like?



I have worked hard to use more left leg in training but the sensor still
says too much right leg power.



Also, I was getting beeps starting and stopping the speed and cadence during
a ride too often until I just changed the battery. Is the symptom of low
battery such behavior? Seems to have stopped now.



Thanks for input.

After riding 700 miles this way all seems to work OK except it is saying
that I am heavily right leg dominant in my pedaling power.

Mine tells me the same thing, even though I'm left handed and left
footed, and I KNOW my left leg works harder. Actualy it reads 50/50
about half the time and 55/45 or even 65/35 the other half of the
time.

I thought about how it must conclude which leg your power is coming
from. After all, it just knows the continuous chain tension and the
instant the right-hand crank passes the chainstay sensor each time
around. It probably attibutes chain tension in the (0.25-0.75)
interval between pulses to be the contribution of the right leg. (BTW
I fooled it by unclipping my right foot entirely. It just a little
pulling up on the left-hand pedal to fool the thing into telling me I
was right-leg dominant.)

This is probably not a bad theoretical approach, but there's
definitely something wrong in the implementation. I won't try to
guess what, but it might have to do with the model's assumptions about
the exact lag time in the chainstay measurement subsystem--since it
probably does filtering, there's going to be some delay.

I have sent some e-mails to Polar.

They have not had the curtesy to respond.
Too bad, thought they were a good company.

"Pete Harris" wrote in message
om...

After riding 700 miles this way all seems to work OK except it is saying
that I am heavily right leg dominant in my pedaling power.

Mine tells me the same thing, even though I'm left handed and left
footed, and I KNOW my left leg works harder. Actualy it reads 50/50
about half the time and 55/45 or even 65/35 the other half of the
time.

I thought about how it must conclude which leg your power is coming
from. After all, it just knows the continuous chain tension and the
instant the right-hand crank passes the chainstay sensor each time
around. It probably attibutes chain tension in the (0.25-0.75)
interval between pulses to be the contribution of the right leg. (BTW
I fooled it by unclipping my right foot entirely. It just a little
pulling up on the left-hand pedal to fool the thing into telling me I
was right-leg dominant.)

This is probably not a bad theoretical approach, but there's
definitely something wrong in the implementation. I won't try to
guess what, but it might have to do with the model's assumptions about
the exact lag time in the chainstay measurement subsystem--since it
probably does filtering, there's going to be some delay.