Most of the international trains in that part of Europe are high speed trains, which are often quite poor at carrying bikes. For the most part, a bike packed to fly will meet the requirements, but options for assembled bikes are very limited. For some reason, ICE trains in Germany, while having the same 120x90 size limit as Thalys and TGV, specify folding bikes only...kind of odd.

All the non-ICE trains in Germany should take your bike, though.
http://bicyclegermany.com/german_trains.html

This page summarises the rules for most trains going in and out of the Netherlands. You may have to travel a more roundabout route on slow trains if you're bringing a fully assembled bike back with you.
http://www.nshispeed.nl/en/before-yo...cycle-with-you