This is Adventure Motorcycle and 4x4 heaven. Not only is the road an awesome ride, but the views, the nature and wildlife, the passes and the end point if you stay over are incredible. It is not a particularly long ride distance wise, but takes the best part of 1.5 to 2 hours from the turn off if you dont stop for pictures or to pass others. However to get to the turn off also involves a pass from the nearest town, so dedicate the best part of a day to get there and back or just stay over. Camp or book a self catering house.
Turn off to Gamkaskloof (the other name for Die Hel)