Ridiculously-specific Polar question: Sensitivity to streetcar cables?

Triathlon Forum
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Here in Toronto we have a decent public transit system, with a relatively extensive network of buses, subways and streetcars (aka trolley cars, or LRT "Light Rail Transit).

I’ve noticed that when I cross street car tracks (and under the power cables), I have no transmission/reception issues. However, if I’m running or riding parallel to the tracks/cables, my HRM goes wonky. It’ll show a “0” in the HR, and when I leave the area of the tracks it’ll return to normal for most of the time…unless I’m in the aero position on the bike, when it’ll register in the 200’s for the HR. Will happen occasionally when I run, too.

Anyone else have the issues? Understandably, the simple solution is to not run or ride near the streetcar lines (always a good idea, as I’ve had some dramatic yard-sale crashes from getting my wheels caught in the tracks), however if I do travel near them briefly and then leave, it buggers up the reception for the rest of the ride. And it can be tough to find routes without tracks in downtown.

2

Its normal. Power transmission lines also cause the same issue.

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Normal
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4

Thanks for the feedback. But any insight on why after I’ve left a cable location the HRM still acts wonky, particularly in the aero position?

5

It’s the magnetic field the body picks up from going next to power lines… kinda like charging a magnet.

Perhaps.

6

Which tranmitter are you wearing, Wearlink or a T31 or T61? Lets start here

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any chance you also use a Cateye with your Polar?

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  1. Not sure of the strap #, but it’s called the “Wearlink” – the soft strap.
  2. I do use a Cateye wireless computer – I know they occasionally interfere with Polar sensors, but I don’t have any issues if I start my HRM before I get near the bike and start the Cateye.
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Since you stated you run and ride, I will assume you have a RS200/400/625x? If you wear the Polar on your wrist and you go aero, you may be exceeding the strength of the Wear Link. Place your wrist unit(Polar) on the stem to experiment, I am sure with aerobars you have limited space, but try to make it work to simulate the position you say gives you wonky readins. My 2 cents, but what do I know…

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Thanks for the feedback, it’s actually a 210, which has been discontinued.

So in your opinion, why is that the Wearlink works fine in aero at any other point OTHER than after I go under the streetcar cables, at which point the whole thing goes to hell?

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You stated
unless I’m in the aero position on the bike, when it’ll register in the 200’s for the HR. I am reading that when you go aero, your HR goes whacky? I would trouble shoot by saying that the Cateye signal is stronger compared to the Wear Link when you go aero. Make sure your Wear Link snaps are always unsnapped and this prevents oxidation. Look for green oxidation on the strap where the snaps go into

12

mine will freak out around houses with alarm systems as well.

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Doggy fences are also a problem
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