If you plan to rent a bike for the island trip, contact us and we will do a reservation for you. Probably we will get a better price if we are organized. I plan to contact the following bike rental:
http://www.lydias-sylt.de/
They have a large choice, including also bikes for children and tandems. Prices start from 5 Euro the day.

Inscriptions for both the island trip and the reservation of a bike on the island can be done following this doodle link:
http://doodle.com/ne7zr9gu3wup6pgt