A nice route I did with a couple of friends some time ago. We started close to Plochingen at a fuel station which is in the greater Stuttgart area. It follows medium to small roads, many curves.
Things to watch out for: Some narrow roads, watch out and stay on your side. Some of the roads are closed on Sundays, especially the road at WP1, but IIRC there was another closures as well (cannot remember, sorry :)).
Nice spots along the route:
- The L1154 around Lorch is an awesome road with great curves, it is worthwhile to wait on either side of the road until there is no traffic. If you are interested in that the Kloster Lorch is a great place to look around (there is also another Kloster later on in Adelberg).
- At WP2 is a nice restaurant with a good view over a lake.
- At WP11 is the “Herrenmühle” which is a great place for quick drink or some food at the end of the tour.
I attached the .kurviger file and the .gpx file for this route.
I hope you will enjoy a nice ride on this beautiful route.