Polar Cadence Sensor

[BMCfan]

Ive taken my cadence sensor of the roadbike and put it on the MTB 4 2morrow arace and i cant seem to get it working. the red light wont flash when the magnet past the sensor, what did i do wrong and how can i quick fix it??

[carlo_sg]

Had the same thing happen with my (wireless) speed sensor when I fitted it to another bike, it was just out of reach of the signal range, so I moved it closer and seemed to work - might be the same problem.

Try taking it off, hold sensor closer to your watch, then move the magnet past the sensor, and see if it works then?

carlo_sg2008-08-01 13:58:54

[Weekend_Warrior]

have u put the watch on the mtb?

 

maybe the batteries are going flat.  didnt u know u never change stuff on your bike the night before a race

[BMCfan]

getting back to this? does the cadence sensor have a battery? if so, how do i change it?

 

and dont anybody have one lying around. i want one for the MTB????

[KayC]

Hi BMC

 

The little red light only works for about 30 sec. to show that the sensor is picking up the magnet moving past.

 

If you want to check it again you must leave it for about 5 mins and try it again.

 

Regards

 

KayC

[Overlord]

getting back to this? does the cadence sensor have a battery? if so' date=' how do i change it?

 

and dont anybody have one lying around. i want one for the MTB????

[/quote']

 

Connect it to 220V and see if it works. If not buy a new one.

[HammerHed]

Yes, it has a battery.

 

You can change it by taking the unit off the bike and looking at the mounting point underneath where it fits on the bike. There are 2 small screws there,  unscrew these and the unit comes apart into 2 parts. Slide the Integrated Circuit card out of the casing and you will see the battery in the IC. It looks like a camera/watch battery you can get from most camera shops.

 

Be careful putting the battery back so that you do  not damage the clip that holds the battery in place as this can cause hassles if the battery comes loose it will stop working.

 

[Speed Devil]

Yes it does have a battery and you can't charge. If it's flat you have to replace it.

I had a similar problem with my speed sensor on my olar S725 just after I bought it. I took it to Polar and it turned out to be a faulty sensor and wasn't giving a strong-enough signal for the head unit to pick up. The little red light also didn't work properly.

 

If it is still under warranty send it to Polar and they will repair/replace for free. 

[HammerHed]

If the signal does not work from the rear wheel side of the bike to the watch on the handlebar, you can move the terminator pin in the IC board to the other position, this will allow a greater signal strength and should then reach the watch on the handlebars.

[Pocketbikes]

The battery it uses is a CR2032. They are between R10 - R15.

 

[Minion]

 

I've tried HammerHed's range extension technique and was somewhat underwhelmed by the result.

I did some informal tests on my desk and found it increased the range by about 50%. I still couldn't mount my speed sensor on the chainstay and there was still only one spot and orientation where the cadence sensor worked.

Surprisingly, I never had these problems on my old bike. It think the old aluminium frame may have acted as some kind of antenna 'booster'.

 

Here's the link to a site explaining the range mod:

http://www.pursuit-performance.com.au/polar/html/local/faq/faq_speed_cadence.html

 

Here's the speed sensor manual with battery replacement instructions:

http://www.polarusa.com/manuals/New_Speed.pdf

Pocketbikes is right on the battery size.

 

Edman2008-08-13 13:08:34

[HammerHed]

I just mount my speed sensor on the front fork facing forward, not the most aerodynamic place but this ensures it works all the time.

 

I did experiment some years ago with mounting it on the seat stay but it was nowhere near as reliable as on the front fork so I live with the aerodynamic compromise.

 

The cadence sensor I mount on the seat tube opposite the front derailleur, this gives no problems at all as far as signal goes.

 

Edman, did you try it on the seat stay? Might be closer to the bars.

 

[Johan Bornman]

Polar's speed sensor is so erratic that I've given up on it except on one of my bikes where it works reasonably OK....for now.

 

Some useless late-nite information on battery size. 2032 translates to a button 20mm in dia and 3.2mm thick. Little bits of trivia like that helps me remember the battery number between checking and when I get to the shop.

 

If anyone can point me to a source for the Polar's wrist unit's battery, a 2354 (I think), I'll be happy. I'm darned if I'm paying R100 again for a two-day battery change operation at Polar.

 

 

[martelpypie]

I think Polar pays all companies to keep that 2354 battery out of SA. I would also like to buy a few. Perhaps a hubber must import it for us all

[Minion]

 

The cadence sensor I mount on the seat tube opposite the front derailleur' date=' this gives no problems at all as far as signal goes.

 

[/quote']

That's actually the only place on the bike where I did get the cadence sensor to work.

In that position, it worked only when pointed so far back that it was almost touching the tyre. Apparently, for best reception, the axis of the sensor needs to be as close as possible to perpendicular to the handelbar axis (something about field lines - not my strong point).

 

I wanted to mount the speed sensor on the rear wheel for use on the IDT, so front fork was out.

It was an interesting experience to discover that sensors that worked perfectly on an aluminium bike became very finicky on a carbon bike, even though some of them were actually closer to the wrist unit.

 

In the end, I solved the problem by buying an Edge 705 (that's my excuse and I'm sticking to it!)

 

[Minion]

 

 

If anyone can point me to a source for the Polar's wrist unit's battery' date=' a 2354 (I think), I'll be happy. I'm darned if I'm paying R100 again for a two-day battery change operation at Polar.[/quote']

 

RS Components in Midrand has them listed in their catalogue for R30:

CR2354

 

You can also get them from Mantech (near Wemmer Pan) for R25:

More CR2354

 

There's also an electronics shop near Wits whose name eludes me at present. I went there once, but apparently it's quite popular with the electrical engineers.

Edman2008-08-13 14:28:00