The Pfalzerwald south of Kaiserslautern is excellent biking country. We stayed our 1st night in Frankenstein just at the north edge of the forests to get a good stArt on the to roads heading south in the morning. (ok and just to get a photie of the sign!
) gorgeous teeny quiet village with a great hotel on a good road.
You been to the Vosges so u just need to nip across the Rhine into the Schwarzwald (Black Forest). Spoilt for choice on the good roads and quaint towns and villages here.
Nothing on par to the Alps though so if you want mind blowing roads and scenery you could keep heading south into the Swiss Alps, east for the top passes (furka/ susten/grimsel) or west for the excellent passes back into France.
The Belgians are the most dangerous bastids in cars I have experienced , watch out!!!