Power Meters

[Paul_nl]

I am now thinking about the polar powermeter. But where do you have to place the normal speedsensor? In charts I saw it on the rear wheel. But I want to place it on my TT bike with disk...

[Tippster]

I am now thinking about the polar powermeter. But where do you have to place the normal speedsensor? In charts I saw it on the rear wheel. But I want to place it on my TT bike with disk...

The speed sensor comes attached to the power sensor. The wire is only long enough to work off the back wheel.

Could a tune magnet not be glued to your disk?

[Samu Ilonen]

I have Polar power meter in my TT bike. Speed magnet is glued near rear hub with 2-side tape.

Cadense magnet fell of today when training, it is very close in front der.



Today's training TT. You see where magnet fell...power goes then down. As you see I started too hard...power is degreasing all the time. First ride on this track and it has 45m climb on ~ middle. Good practice anyway.

[John979]

I spent the afternoon wiring up my mountain bike with a Polar PM so I can get an idea of how much energy I expend on my recovery, off-road and winter rides. Of course the speed sensor does not work, but I am in no rush to change it as speed doesn't matter much anyway...

[Samu Ilonen]

Why not? Just put one more magnet to rear wheel...

[John979]

Why not? Just put one more magnet to rear wheel...

The magnet is fine; it appears something is wrong with the speed sensor. I am going to work on it more today. Again, its not a big issue as I am more concerned with time, kilojoules and TTS (from Cycling Peaks Software) than distance. This is not my primary bike and is only used for recovery and winter riding.

[Paul_nl]

The speed sensor comes attached to the power sensor. The wire is only long enough to work off the back wheel.

Could a tune magnet not be glued to your disk?

Hmm, maybe.

But with the polar S725 you also get a speedsensor. Is it possible to use that wireless speedsensor with the S725 while you are using the powermeter as well?

[Tippster]

The speed sensor comes attached to the power sensor. The wire is only long enough to work off the back wheel.

Could a tune magnet not be glued to your disk?

Hmm, maybe.

But with the polar S725 you also get a speedsensor. Is it possible to use that wireless speedsensor with the S725 while you are using the powermeter as well?

The power kit works differently.

The bar mount for the watch unit has a battery in it. The unit doesn't work wirelessly. A wire from both the speed sensor and power / cadence kit runs to the bar mount.

I'd be surprised if the watch unit could cope with a wireless speed signal while mounted on the Power specific bar mount.

I'd recommend e-mailing Polar direct...

[Samu Ilonen]

No,no...I have to change from watch to "Power Off" when I ride my road bike without power meter with normal Polar cadence/speed monitors or nothing works. not a big deal but must do.

[nrhorwitz]

I'll be getting a powertap SL shortly. Does anybody know if the "problems" Cycleops has been experiencing with Powertap SL has been solved (i.e. battery, etc)?

[Tippster]

I have Polar power meter in my TT bike. Speed magnet is glued near rear hub with 2-side tape.

Cadense magnet fell of today when training, it is very close in front der.



Today's training TT. You see where magnet fell...power goes then down. As you see I started too hard...power is degreasing all the time. First ride on this track and it has 45m climb on ~ middle. Good practice anyway.

I've found that when you place the speed magnet near the rear hub, I can catch the rear mech when in the large cog at teh back. Better to place your speed maget half way along the spoke - the wheel dishing then takes the maget away from the rear mech.

For this to work you need the power kit close to the cranks and the speed sensor half tucked under the power kit.

My cadence sensor is 3/4's along my crank away from the BB. Did you use the tape to fix the cadence sensor. I've used mine off-road and still holds fast...

[mises]

[quote="Tippster]For this to work you need the power kit close to the cranks and the speed sensor half tucked under the power kit.
quote]

I thought the speed sensor had to be on the non-drive side chainstay or the power sensor would interfere with the readings.

[Tippster]

[quote="Tippster]For this to work you need the power kit close to the cranks and the speed sensor half tucked under the power kit.


I thought the speed sensor had to be on the non-drive side chainstay or the power sensor would interfere with the readings.

I must confess that I didn't read the instructions in detail.

the power sensor does not interfere with the speed sensor.

Their doesn't appear to be enough wire to fix the speed sensor to the opposite chainstay anyway.

[nrhorwitz]

No,no...I have to change from watch to "Power Off" when I ride my road bike without power meter with normal Polar cadence/speed monitors or nothing works. not a big deal but must do.

FYI- I got it 2 days ago and so far, it's working beautifully. Now I have to wait for that usb-serial converter before i can start downloading the data into the laptop.

[wdbike.com]

Check out www.ibikesports.com - a brand new device that measures power via wind velocity, and is surprisingly well-designed. I was talking to the designers a bit at Interbike and they definitely seemed to have very elegant answers to all of the questions I had.

Nobody knows yet if it's as accurate as PT or SRMs (though ibike is making claims to that effect), but it weighs 58g with harness and wheel magnet and will be a welcome addition to my racing setup next spring. I am already certain they'll be more accurate than the Polar meter - and they'll cost only $350 retail.

We're hoping to have them in stock by December and will test them against our PTs. The company is doing their professional testing right now.

wdbike.com