Distance Indoor with a garmin forerunner and cadence sensor

kirkjr13

Is it possible to record the distance that you cycle on a turbo trainer indoors with a garmin forerunner 305 with the cadence sensor. I get cadence readings okay but nothing appears in the speed/distance column???

Simon Notley

Assuming the speed part of the sensor is working correctly (i.e. you have the magnet on your back wheel etc.) I think you should be able to get speed data. You might need to turn off the GPS by going to settings>system>general (I think, that's just from memory). I can;t tell you for certain if this works as I don't have the cadence sensor myself.

GavH

kirkjr13 wrote:

Is it possible to record the distance that you cycle on a turbo trainer indoors with a garmin forerunner 305 with the cadence sensor. I get cadence readings okay but nothing appears in the speed/distance column???

Yes is the simple answer. Why you are not getting it I do not know. Setup correct? You should not need to turn off the GPS. The Garmin units will default to the GSC 10 sensor over GPS automatically. I don't turn my GPS off and my GSC10 reports speed and distance to the head unit just fine. Have you tried resetting the GSC10 and then looking for the red or green flash each time the magenet passes? (One colour is for the speed/distance magnet on the rear wheel, the other for the crank magnet - I can't remember which is which).

lochindaal

On the Edge 305 you have to turn of the GPS to get the distance to work for indoor training.

You always see the speed figure though even with GPS on so it sounds like your magnet is not set correctly.

kirkjr13

Firstly can i apologise for my poor English last night, I was clearly more tired than I realised.

I have set up my magnets as per the instructions and I get the light flashing for the pedal magnet but not the wheel. How close do they have to be? Even when then are almost touching it doesn't register. I've tried it was gps on and off.

Thanks for the help so far though.

kinesin

Does the GPS and Cadence work outside?

The readme says mentions the Cadence sensor/GPS auto calibrates the wheel size, IIRC this is over 1km (maybe more).
If this hasn't been done (i.e. the sensor was fitted to the bike on the turbo indoors) it might be root cause of the issue.

The main body of the GCS10 should be fitted so the marked line matches the passing of the pedal magnet, and be within 5mm, the movable arm should then be adjusted to get within 5mm of the wheel magnet, again lining up the mark/magnet.

kirkjr13

I've rechecked all of the measurements and alignment and can't find what I've done wrong. Think this one might need to be handed back to garmin for their input!?!

lochindaal

kirkjr13, I'll ask what may be a stupid question.

Do you realise you can undo the screw on the sensor and rotate the speed sensing arm? This allows it to get the right distance from the magnet.

GavH

Have you also tried a different magnet and just pass it up and down past the sensor to see if the green light flashes? Spare (generic) magnets can be had on ebay for a little over £1 inc postage.

kirkjr13

lochindaal, i'm not quite that bad!! i have manoeuvred the sensor arm until there is barely any gap at all between the magnet and the sensor. Part of the problem is that I'm not positive it has ever worked as I have only just started to train indoors with it and the gps takes over outside.

I've just acquired a spoke magnet (for free from the llb) and will have a go with that tomorrow.

thanks for all the suggestions so far.

Simon Notley

It's quite possible the the sensor if faulty. They're not known for their reliability. Garmin will replace if it's less than a year old.

Simon