Assuming you decide to take your bike with you, you need to box it so it does not get too damaged in the getting to your destination.
First aside: One of my readers suggests that rather than boxing a bike like I describe here, simply buy a good bicycle bag from a bike shop and disassemble your bike enough to fit in the bag (see below). She has used her bags more than 14 times on overseas trips and have had only one problem with damage. She recommends Cyclepro bags.
Second aside: Another reader suggested that all you need to do is remove the pedals, partially deflate the tires, and loosen the stem to turn the handlebar. Then bag it in the heavy bag the airline provides and you're done. If you are inventive, you may find a good use for duct tape in this process. Actually, I think most bikes are handled in this manner.
You can either have the bike boxed by a bike shop or follow these directions regarding boxing. Once your bike is boxed, consider putting it inside another, slightly larger box and pad any air space between the two boxes with cardboard or bubble wrap.
The larger box can be found at America's Amtrak for $7 each. They are nice, roomy, and built to carry bicycles. In fact, if you ask Amtrak may give you a used box free; they gave me one. The smaller boxes can be found at your local bike shop. Bicycle stores throw away the boxes that new bikes come in. These boxes can be challenging because new bikes come broken down to keep the package size as small as possible. I have found that one has to call ahead to bike stores because some recycle the cardboard as soon as they unbox the bike that it came around. If they want to charge you, find a better bike shop to patronize.
The instructions below are detailed and thorough. When I shipped my bike, I didn’t have the advantage of this list. Consequently, I only thought of some of the things the list recommends. The bike got there fine – perhaps I was lucky. I also wrapped the entire bike box in plastic wrap when I was done. And I packed the panniers, etc. along with the bike. One local hardware store even offered to shrink-wrap the bike in plastic once I had it dissembled. I thought this might be overkill, so I passed up the offer - but it certainly would have worked.
Once at your destination, you would be well advised to save your packaging materials for the trip home. Most airports and train stations have storage services but they cost a bit. Many people ask their first overnight accommodation to store the materials until you return at the end of your ride. It is a good idea to make sure this is possible when you make reservations.
Lastly, remember to take enough tools in your other luggage to put your bike back together again upon arrival. Since 9/11/2001, this could be problematic if you carry everything on.
Disassembling your bicycle for shipping:
Preparing the Box:
Note: We copied these steps with permission from The Cyclists’ Yellow Pages, 1999 Edition, by Adventure Cycling Association.
Send your bike by freight ahead: One more thought belongs here on the How to Pack a Bike page. Some of the freight forwarding firms in Germany (or around the world) will ship your bicycle to a physical address (house number, street, and city with postal code) for a fee (starts around €30). One such firm is Hermes Versand Service. If you are traveling by Deutsche Bahn (rail), you can organize sending your bicycle by freight from house to house at least 2 days prior to your planned arrival at your destination by calling DB's Hotline 0180-5-99-66-33 (the fee for this hotline is €0.14/minute from a landline, €0.42/minute from a mobile phone). One can also Google "Hermes Verstand." It is not inexpensive to ship a bicycle within Germany but it is convenient. You can pack your bike for shipment or Hermes will pack it for you for an additional €6 - €7 per bicycle.