The Romantic Road (Germay) on a carbon road bike

The Romantic Road cycle route is quite rough in parts, but an MTB is not necessary. We met somebody this year on the route using Dutch sit up and beg bikes. The majority of folk en route use bicycles with wider tyres. With the help of the ADFC BVA maps it is possible to work out a route on minor roads running parallel to the official route when needed. If memory serves correctly: Leaving Würzburg there are a few km of non-tarred track. The Tauber Valley to Rothenburg and the Franconian Heights to Feuchtwangen are fine. Between Feuchtwangen and Dinkelsbuehl is not good for carbon road bikes. From Dinkelsbuehl to the the Danube is OK. On the stretch somewhere south of Rain into Augsburg you would need to follow minor roads. The official route follows the towpath along the river Lech and that is bumpy. South of Augsburgs to Landsberg is also rough through the woods. You could follow the Via Claudia Augusta from Donauwoerth to Füssen which is on minor roads and tarred cycle tracks. Some of the historic towns have historic cobbles which might not be good for a carbon frame. The original Romantic Road car route has very heavy lorry traffic in parts and some motorway like stretches. The scenery between the towns is superb and the towns themselves are magnificent with fantastic baroque churches. The food is solid. The portions are immense. The beer is Bavarian. Who could want more?
I suspect you would be happier on a steel or Al bike. Our guide to the route does follow the official route. It is being revised and reprinted at the moment. There is an article in "Crazy Guy on a Bike" by us about day trips from the towns and villages en route which might well give you some ideas to bypass the rough bits.
Neil Forsyth, Bergstrasse Bike Books