Garmin Spoke Magnet Issue

badhorsy

I'm using a Garmin Edge 800 with the speed/cadence sensor.

Is there anyway to explicitly check whether a spoke magnet is working or not (since if it doesn't, the speed will still register through GPS)?

I tried resetting the unit (by holding down the outside button). When I do this, the unit flashes red whenever the cadence magnet moves past it, but does not flash when the spoke magnet passes it. The spoke magnet is easily within range though, and passes very close to the arm.

Is something wrong?

meanredspider

The light should flash (green?) when the spoke magnet passes - you can adjust the arm to achieve this.

Not sure what it's for though - I can only assume that the system uses this to smooth out speeds - especially when GPS coverage maybe shaky. I use/used my Forerunner 305 on my road bike with cadence sensor on my roadbike and without on my MTB - not noticed a difference.

tmg

It needs to be passing the exact bit on the arm where the sensor is, so I would suggest re-reading through the set up instructions to make sure everything is lined up as it should be

Lucky Douglas

Find a way to spin the wheel without the bike moving. GPS will think the bike is still, cadence monitor will think it's moving.

Skerryman

meanredspider wrote:

The light should flash (green?) when the spoke magnet passes - you can adjust the arm to achieve this.

Not sure what it's for though - I can only assume that the system uses this to smooth out speeds - especially when GPS coverage maybe shaky. I use/used my Forerunner 305 on my road bike with cadence sensor on my roadbike and without on my MTB - not noticed a difference.

As far as I know it uses it to calculate speeds and failing that the GPS does the job (or possibly the other way around). Dead handy for trainer use though!!

niblue

I'm pretty sure the forerunner 305 only uses the speed sensor when it doesn't have a GPS signal - not sure if the Edge 800 is the same.

I'm planning to get the speed/cadence sensor for my 305 for use on the turbo, and when doing that I'll turn the GPS off so the speed sensor has to be used.

SBezza

Hold back wheel of the ground, spin it and see if a speed registers on the 800, if not the sensor is not picking up the wheel rotation. It needs to be fairly close to trigger the internal switch of the sensor.

Skerryman

5 mm according to the manual

Chrissz

Press and hold the reset button on the sensor (on the chainstay) then spin the wheel - there should be a green flash every time the wheel magnet goes past the sensor and a red one for the cadence magnet.

1_reaper

Chrissz wrote:

Press and hold the reset button on the sensor (on the chainstay) then spin the wheel - there should be a green flash every time the wheel magnet goes past the sensor and a red one for the cadence magnet.

Spot on

John.T

I tried resetting the unit (by holding down the outside button). When I do this, the unit flashes red whenever the cadence magnet moves past it, but does not flash when the spoke magnet passes it. The spoke magnet is easily within range though, and passes very close to the arm.

Quote from OP. He has done that check. If the screw holding the sensor is tight and passing a magnet very close to it by hand does not make the green light flash I would suspect a faulty GSC10 unit.

R8JimBob88

Ive always noticed the green light flashing every time the magnet passes on mine too. Yet today after cleaning the bike it doesn't seem to anymore.... The red cadence one still works.

Still seems to work though, I switched the gps off and the sensor still records my speed. Must be a dodgey green led? Although this sounds unlikely