Polar Power Sensor Installation

Quoted message said:

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" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Quoted message said:

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.