Best going south, bumpy sections but done it a hundred times so know where to be careful. Fun ride but look out for bumps in middle of corners!
Just by Bolkesjø, turn North. This route takes you through beautiful scenery, but unfortunately on poor road-surface. Lots of good places to stop to enjoy the views, but not many amenities. Can either be combined with a trip North over the mountain (towards Geilo, and possibly then West towards Bergen) or just around the Tinn Lake (spectacular).