i assume you're taking Eurostar to Paris. If so, you'll need a bike bag but they won't charge for it. If you have a folding bike bag then you can ride to the station and then bag the bike before going onto the train. Not too sure about the trains around Europe but it should be possible (maybe by booking ahead) to put in a luggage car or something without taking it apart. If you have a bike bag with you then that is a good back up.
i assume you're taking Eurostar to Paris. If so, you'll need a bike bag but they won't charge for it. If you have a folding bike bag then you can ride to the station and then bag the bike before going onto the train. Not too sure about the trains around Europe but it should be possible (maybe by booking ahead) to put in a luggage car or something without taking it apart. If you have a bike bag with you then that is a good back up.