What happens if I've completed the distance but I'm not yet in the 5km finish radius?

In this case, you must continue the ride until you enter the finish radius. The app recognizes this and then finishes...

In this case, you must continue the ride until you enter the finish radius. The app recognizes this and then finishes the ride automatically. The ride will be rated in the distance category you originally selected, regardless of how far you had to extend the ride.