Holland has an extensive rail network with regular services all over the country. You can get from one side of the country to the other with your bicycle in a matter of hours. This makes the train a good way of exploring different parts of Holland.
Visiting the Dutch Wadden Islands, island hopping or crossing the many rivers and canals: ferries are an important means of public transport in Holland. Taking your bicycle is never a problem, though there might be an extra charge.