I've discovered in Bike mode, regardless of your real track, the gps track will only lock on a road you are riding on or near. The watch, by default, is set to LOCK ON ROAD.....I was riding a new bike path but after downloading ride it places me along a road nearby because the bike path wasn't on watches built in map. Just an FYI for others confused on their bike tracks. It doesn't do this for Walk, Run, or Trail Run modes. To fix, go to SETTINGS-MAP-deselect LOCK ON ROAD.
actual route is the light blue cyan line, the watch LOCKED ON ROAD in red because it didnt know there was a bike path there.