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520 keeps dropping the Speed and Cadence sensors.

Hi all,

I've been using the 520 for a few weeks and for the life of me I can't figure out why it keeps dropping the signal to the speed and cadence sensors. I'm using the ones that came with the bundle so they're separate devices unlike the GSC-10 I used to have. I haven't tested/noticed it on outdoor rides but since most of my weekday training is on on an indoor trainer with pre planned workouts, this is a bit of a deal breaker for me if I can't get it solved.

Link of this mornings workout showing it cutting in and out during my intervals

https://www.strava.com/activities/416751717/overview

In previous workouts it would automatically auto-pause, I since then have turned that feature off.

(Saturday's trainer ride it was non-stop) https://www.strava.com/activities/414722987

Has anyone had this problem? Any help would be appreciated

Thanks!

0 krazyeone over 9 years ago

I don't have 520 but I can suggest two things:

1.Activate 1 second recording
2.Check if there are a lot of metal around your trainer

0 Former Member over 9 years ago

There are reports of issues with magnetic based trainers, protective gel on the batteries when shipped that needs cleaning off and magnatised chains in the Speed/Cadence Sensor forum https://forums.garmin.com/forumdisplay.php?463-Speed-Cadence-Sensor.

0 Former Member over 9 years ago

If you are dropping both speed and cadence it may be interference with the ANT+ signal. WiFi is on the same frequency and can be a problem.
Also the speed sensor senses the earth's magnetic field so using it on a magnetic trainer can be a problem.

0 8BITMARLON over 9 years ago

Thanks for the info guys, there are a few computrainers side by side during my training sessions, I'm not sure if they're magnetic or not. I've wiped clean the sensor and switched the recording to 1sec. I'll test it during training tomorrow morning and see what comes of it. If not I'm ditching this new system and going back to the GSC-10 that's never failed me.

0 Former Member over 9 years ago

Also getting signal drop on 520

Same problem with garmin 520
no magnetic trainer anywhere, garmin speed cadence and heartrate thingy and powertap.
Never ever had a problem on my Garmin 500 or 800, had nothing but aggro with this unit.

Firstly it started saving rides with random dates LOL..... took me a week to workout that rides had been uploaded, but 2 months back, did factory reset, now keep getting ant+ signal drop off all sensors (cant be all the batteries at once!). Unit is 98% charged,
Will speak to customer support tommorow. Will let you know

0 aweatherall over 9 years ago

When you say Powertap are you talking about the G3 or P1 or C1.

If it is the G3 then speed will come from the hub and that will take priority over the speed data from an external speed sensor. Also if it the G3 you cannot install the magnet less speed sensor on the Powertap hub as the electronic in the hub will interfere with it.

0 rodrigovalle over 9 years ago

When say Powertap are you talking about the G3 or P1 or C1.

If it is the G3 then speed will come from the hub and that will take priority over the speed data from an external speed sensor. Also if it the G3 you cannot install the magnet less speed sensor on the Powertap hub as the electronic in the hub will interfere with it.

From DCRainmaker (http://www.dcrainmaker.com/2014/05/garmins-spd-cad-magnetless-sensors.html):
"Garmin believes that the noisiness of the speed sensor I’m seeing is due to placing it on a PowerTap wheel, which they believe is introducing interference. They suggested instead putting it on another wheel. In doing that, I’m seeing much better results"

Rodrigo Valle

0 aweatherall over 9 years ago

Yes the G3 will interfere with a the speed sensor. You don't need a speed sensor if you have a G3 as that sends speed data.

0 Former Member over 9 years ago

I'm getting these drop too, but only from Speed sensor, and only when I ride with Vector pedals (my Tri bike).

Cadence is reported fine. But speed may eventually drop to a half (or zero, triggering auto-pause for a second). I replaced the battery, re-paired the sensor. Still having these issues. I ordered another Speed sensor, will see it it solves the problem.

0 aweatherall over 9 years ago

When riding with the Vector system the cadence will come from the Vector system and not the cadence sensor.

I suspect that the problem is some magnetization in the drive chain of the Tri bike that is causing an issue. Try putting the speed sensor on the hub of the front wheel and see if that fixes the issue.