This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Garmin Edge 830 shows incorrect speed (no speed sensor).

9210857
over 3 years ago

I have a new Edge 830 (purchased in April from Amazon) that is problematic.  The issue is that the speed on the head unit is not accurate and varies from 0.5 MPH to 10 MPH below the actual speed. What is crazy is that I have a Garmin watch (945) that shows the correct speed.

I know the correct speed because right now I am comparing the displayed speed on the head unit against my watch, my cell phone running RideWithGPS, with an old Cat-Eye cycle computer and with all the people I am riding with. All but the Garmin head unit are very close to each other.

Being 0.5 MPH down is not terrible but being 2-3 MPH off is annoying and impacts my group rides. 

And, what is worse is that for 5-10 minutes stretches, the speed will be 10-14 MPH lower than I am going. That is, I am going 20 MPH, and it will say I am going 7 MPH.

I don't have a speed sensor but am not sure why my watch and phone can use GPS, when the head unit using GPS+satellites is so poor.

Any tricks to get this to work correctly? Or do you have to use the speed sensor with this?

  • 0 over 3 years ago

    Same problem here today. No speed sensor. V9.4 on my 830. Speed was behaving erratically, often at exactly half the correct speed compared to my other speedometer. I was also wearing a garmin Bluetooth heart monitor. It too was going bizerk, clipping at 30 bpm over normal for several minutes. I eventually stopped and changed the satellite settings from Glonass to Galileo. That seems to fix it for now. I’ll give it another try tomorrow. Don’t if it’s a v9.4 problem, it showed up on my device about two weeks ago.