The European East Pass covers Slovakia, Hungary, and Poland in addition to Austria and the Czech Republic. Or you can forget about passes altogether and take a slow train through Bohemia, enjoying the Czech countryside en route to Karlsbad. Rent your own sailboat or motorboat and cruise at your own pace. Boat rentals can be bareboat or crewed, so you don't have to be an old salt to rent one. Sign up for a luxurious barge cruise in Western Europe, or rent your own budget barge.
Many companies offer bike and barge holidays in Holland, and some are offered in other countries.
If you tire of riding your bike, just stay on the ship and laze around. Most bike and barge trips are in well-touristed areas. Bike Europe Bike your way around Europe, camping at night or staying in inns. Some travel agencies offer gourmet bike tours, or DIY bike trips. Go with a group or independently.