I have an 800, should be the same as 820 (guessing). I use RideWithGPS for all routing as I find their route builder works best for me. I usually have my 800 USB connected/charging while I plan, then download either the gpx or tcx file to my Garmin "new" folder. AFAIK when you power up the Garmin it will take any files found in the folder, convert to binary as necessary and resave them. For 800 I think you can use gpx and have the Garmin generate turn anticipation for you, with tcx you also get turn alerting from the "route sheet" waypoints (so tcx works with GPS units without on-board routing). I think you have to have a paid RwGPS account to edit the "route sheet" (haven't done a route in a while), but that's never been a need for me.

I know the 820 is bit different from the 800/810 but hopefully the above applies.

scott s.
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