fras says:

if i run at about 5.10 per km the watch shows my pace correctly, but once i start going faster the pace on the watch gets slower to around 6.30

I presume the battery is going? The sensor is about 8 months old. I just didn't expect it to happen this way i thought it would just stop working.

 MarkedMan says:

Is the sensor slipping in your shoe? As you go faster it may be slipping more.

 fras says:

it's in one of those lace pouches quite tight, i'll double check though thanks.

For anyone who has had to replace a sensor, how did it run out?

 beerRahn says:

On the Ipod version, a message comes up saying the battery is getting low. Then a few days later, it will fail to find the sensor.
Mid run? Beats me what would happen.

 PotatoHead says:

I am not an expert on this -- and I do not know if the information I've read is reliable. But many people have written that the sensor is basically a wireless pedometer -- nothing more. So if lengthen your stride when you speed up, you will take fewer strides, and the sensor therefore would count less distance for a given amount of time -- making it seem like you are running slower, when you are really running faster. I thought the sensor was more complicated than that, but maybe that's true.

 fras says:

thanks for the feedback, there is definitely something out of the ordinary going on though as it usually tracks my speed increases fine.

Bigrhan brings up a good point about the battery low message, i'm pretty sure this is supposed to happen with the sportband too.

I ordered a new sensor today anyway so i'll report back with how it goes once it arrives.

 GrooveButcher says:

As I gave up completely trusting the sensor for its readings, I now always run with both Nike+ and a Garmin Forerunner for the supposedly more precise GPS readings.

I can confirm that if you run faster than your normal pace, the sensor will give a shorter distance reading (making you seem much slower), and if you run a lot slower, the sensor tends to give a longer distance reading, making you seem much faster, which of course could be beneficial ;-)

My experience has basically shown me that Nike+ is a fun tool to be able to upload your runs to sites like this, but for real distances and run tracking, you can't beat GPS trackers.

 malweth says:

I don't have a forerunner, so it could be my aged Handheld GPS, but I find the Nike+ sensor to be significantly more consistent. I can't comment on its accuracy, though - I have nothing to measure against... (It is quite accurate to "google pedometer" and the like).