I'm planning next year's trip to Germany. Like this year (see https://yacf.co.uk/forum/index.php?topic=110424.0) I intend to get to Cologne and then follow the Hamburg-Berlin-Koln audax route.
This time I intend to take the Eurostar to Brussels, then Belgian IC to Welkenraedt (as suggested by Ivo in reply 4 here https://yacf.co.uk/forum/index.php?topic=108407.0), and cycle over the border to a hotel in the Eifel region of Germany. The next day I'd need to ride from there (think Düren or Nideggen or Euskirchen) to Cologne. Does anybody know of any good routes, or am I best just using my preferred mapping application (ridewithgps) and using as many bike paths as possible?
I guess there's a secondary question in here - how do others plan bike-friendly routes in Europe (I'm actually only interested in Germany)? I need surfaces which are good for a 25mm-tyred light tourer/audax bike (Tifosi CK7) and I'm not keen on cycling in heavy traffic on holiday.
Komoot will tell you what open street map thinks the road surface is. This can vary a bit, but is mostly accurate. I use it to avoid pave.
There are some long distance routes that can be quite nice, and are sign posted, but often they are a bit like sustrans (longest route between 2 points).
I've yet to have a trip to Germany that hasn't involved at least 1 angry driver shouting something out the window at me.
No route planner is perfect, you're just working to improve the odds that what you intended to do is rideable. On todays 60k ride, strava tried to take me through a military base, and down 2 foot paths that did not permit cycling...
Komoot, Ride with gps, strava, cycle streets, google, all of these need an "avoid stairs" option. Something you wouldn't think would be needed, but apparently they all think stairs are ok to cycle down...
Komoot also sent me down the a14 dual carriage way near Cambridge...
Google maps almost got me shot.
Only komoot seems to realise its a good idea to mention that ferries exist.
In your case, crossing the border from Belgium into Germany, try to pick up the Vennbahn.
Getting to Koln, find the Rhine, follow it. The Rhine cycle path is usable most months of the year (kayak needed some months due to flooding).
J