Speed on my edge 305 does not work when gps disabled

albob

Hi,
I am trying to use my edge 305 indoors on a turbo trainer. I have the cadence sensor and the magnet on the spoke. I have also disabled GPS. When I spin the wheel I can hear the sensor clicking whenever the magnet passes it so I assume that it is close enough. However i can't get a speed reading on my unit. Is it broken? Any suggestions? As a cadence sensor it works fine.

Also is there any change that the magnet brake on the turbo could be affecting the speedo or my HRM. The HRM is acting up too and I never had an issue with it before.

Thanks

paddymacsporran

For cadence, ensure the unit is re-set, the instructions can be found on the support section of the Garmin website. I've went through three of them as warranty replacements on my 705. There's a little red/green light that tells you if the signal is being picked up.

I didn't bother when the 3rd one went, now I just count......

Re the HRM, mine went doo-lally and I replaced the battery, it's been fine since.

Re getting a speed reading, it won't happen as the unit is static, the gps is disabled and you're indoors. Speed reading is nothing to do with the magnet, it reads the gps signal from the sky. For turbo's, Garmins are as useless as an old-school Dalek on stairs.

Lumen

paddymacsporran wrote: »

Re getting a speed reading, it won't happen as the unit is static, the gps is disabled and you're indoors. Speed reading is nothing to do with the magnet, it reads the gps signal from the sky.

The whole point of the speed sensor is to give speed readings when the GPS is off or cannot get a signal.

Coronal

albob wrote: »

However i can't get a speed reading on my unit.

Have you input the wheel circumference? I think the default setting is for the GPS to calibrate it each time and then the cadence sensor can work out the speed.

paddymacsporran

Lumen wrote: »

The whole point of the speed sensor is to give speed readings when the GPS is off or cannot get a signal.

It's a cadence sensor, it just measures the revs of the crank. Don't think it measures speed.

Raam

Speed on a turbo? You are supposed to measure effort by how much drool is seeping out of the side of your mouth.

Lumen

paddymacsporran wrote: »

It's a cadence sensor, it just measures the revs of the crank. Don't think it measures speed.

This?



It's a speed and cadence sensor, hence the title. The cadence is detected from the crank magnet, the speed is detected from the spoke magnet.

Raam

I managed to get the cadence sensor working for speed on the rollers, but it was flakey as hell. Can't be bothered with it tbh.

Freddy687

You do not need to disable the gps.
The unit will use the sensor if the GPS is missing or not moving.
The method I use to connect a sensor is this:
Puting the garmin on the ground beside the sensor, makes it easier.
1. Make sure you have "Sensor mounted" clicked in the Bike Profile.
2. Set the wheel diameter to custom and the tyre size to 2097mm. Assuming it is a road bike with 700c tyres.
3. Go to the accessories menu and click "re-scan" for the cadence sensor.
4. Go back to the main screen. The 305 does not beep when it finds accessories.
5. Press the reset button on the cadence sensor.
6. Spin the cranks backwards and check that the Red led is blinking.
7. Do this for 5-10 revs.
8. Turn the cranks forward and check that the Green Led lights for the wheel magnet.
9. Keep an eye on the Garmin to see if it has connected.

If that does not do it change the battery and try again.

albob

Hi all,
Thanks for your replies. I tried resetting the sensor. As I said earlier the cadence part of the sensor works fine and I get the red light when I turn the cranks backwards. However I don't get any green light when I pedal forwards. I have the magnet lined up with the line on the arm on the sensor and do hear a click every time the magnet passes it....but no green light or reading on my garmin.

How long should the battery last? Probably about time I changed. I'll loko through previous posts for a place to buy.

Bought my Garmin in the states so must up the warrenty side of it.

As for using speed on a Turbo....Tacx interval plans refer to speed in some sections. Not sure about it myself but willing to give it a go.

Thanks

Keep_Her_Lit

paddymacsporran wrote: »

as useless as an old-school Dalek on stairs.

Great phrase! Love it