The idea for this trip came in the winter of 2015/2016. I had really enjoyed my first bike trip from Berlin to Usedom the previous spring and was aching to get going again.
This time I wanted to try my tour the other way round: take public transport somewhere and then ride back home.
This time I opted for a flat ride, so going along a river seemed the ideal track for this endeavor. The Elbe River quickly seemed like a good choice. It has a fantastic infrastructure and basically you can keep on going forever. (Upstream the Elbe Trail runs from Cuxhaven all the way to its spring in the Czech Republic, all in all over 1180km)
The whole track of the Elbe River Trail is shown here: http://radreise-wiki.de/Elbe, the Havel-Rad-Trail I took on the last day can be viewed here: http://radreise-wiki.de/Havel
I only had 3 days and felt like taking it easy compared to the Usedom-trip, so it was clear from the get go, that I would have to skip parts in order to get all the way from Hamburg to Berlin in that time.