Friends are renting bikes in Bilbao and dropping them off two weeks later in Valencia. I thought I would make a forum post in case anyone here is interested in such a service. I think the one way feature is a real perk. Of course, round trip is also an option.

Cycling rentals.

Thank you for sharing. That's definitely a service I'll keep in mind. I'm currently planning a trip that will include cycling the Loire and the best  I can find for one way rental is Nantes to Orleans. Nothing of greater distance. 

There are many trains going along the Loire. We rented bikes for our grandkids last year, in Nantes, took a train out towards Orleans, and pedalled back to Nantes to return them. Presumably one could adapt this method to a longer distance tour.

Maybe I need to start a preliminary trip journal. The train would work when I'm retired and time isn't an issue. I'll have a month of vacation and this is going to be a one way trip. Current plan is to fly to London and do some sightseeing/pub crawling, then head to Cambridge with an excursion to IWM Duxford.  Ferry across to France, do Normandy, then to Nantes and get bikes to go up as far as Orleans. Train to Limoges for a visit to Oradour-sur-Glane, then to Alsace and a bit of Germany before flying out through Frankfurt.