Many people romanticize rail travel, even though the age of billowing steam and luxiurious passenger coaches has long since passed. Still, taking the train can be a good way to get to your destination in Europe without having to deal with traffic, or worse yet, finding a place to park your car. Here in Germany, the national rail line, or Deutsche Bahn as it is known, is fairly accomodating of travellers on bike. In neighboring Netherlands, you can also travel with your bike fairly easily, but it is a bit more complicated.
When you wish to bring your bike aboard a train in Germany, you purchase fare for yourself and then separate fare for your two-wheeled companion. This is known as a Fahrradkarte or a bicycle ticket. Typically, they are €5-6 and are valid for one day of travel. This can be done online, at a ticket counter, or at a kiosk on the platform, wherever you are purchasing your own train ticket. Some of the long-distance trains, such as ICE lines, usually require a bike reservation as well. On a local train, you'll just need to locate the train car with the bicycle emblem, and bring your bike inside.
As I mentioned, if you're travelling in the Netherlands, it is slightly more complicated. This is because there are several different lines operating on the Dutch railway network, some of which charge extra for a bicycle and some that do not. NS, the primary state-operated line, requires a bike ticket whereas on Veolia you can roll your bike onto the train no questions asked. This policy, of course, can lead to many bicycles in a car at once, and as victim to it I once ended up having to stand with my bike in the bathroom for the duration of my journey. (The real victims in this case were those that needed to use the bathroom I occupied.)
So, depending on where you are going, you may end up transfering onto several different lines, and its best to know beforehand whether or not you require a bike ticket. The ignorant American technique only works 67% of the time, otherwise you'll end up paying a fine.
Another distinction you might find interesting is that on Germany railways, you can drink a beer or any beverage you'd like, whereas on Dutch trains, public consumption of alcohol is expressly forbidden.
Either way, one shouldn't shy away from utilizing a country's train system when travelling via bicycle. It really shortens the time between two waypoints and gives you a chance to relax, talk to others, and adjust those things on your bike that you've been meaning to for the last 40 kilometers. And even if you find yourself travelling by train without a bicycle, many major hubs have them available for rent. Germany offers the Call-a-Bike in every major city, and the Netherlands have their OV Fiets avaiable at just about every railway station in the country, usually for less than €10 a day.
Of course, cost is always a factor, and in some cases a train ticket might set you back more than you can afford, so be sure to keep an eye out for special deals. These are offered at different convenience stores or online. Also, travelling in groups is almost always cheaper than travelling alone, so if you've got two or three more people headed to the same place, a group ticket may be a very affordable option. And if you're planning on spending a long period of time riding the rails, a pass might be your best option. Here are some links that will help you out on your journey:
http://www.raileurope.com/index.html [All of Europe]
http://www.eurail.com/europe-by-train/itineraries
http://www.bahn.de/p_en/view/index.shtml [Germany]
http://www.ns.nl/en/travellers/home [Netherlands]
- Bicyclist Abroad