The Chateau at Chaumont-sur-Loire is excellent, compact but beautiful outside and the displays on the interior were much better than I expected. I can take or leave the modern art displays, a few were interesting and some seemed to me to detract from the Chateau. However, everything is superbly arranged, with excellent information in different languages (English & German included). Stunning gardens, again some of the art is odd but each to their own. Do not miss the excellent stables.
I actually much preferred our visit here to Chateau Chambord.
For cyclists there are ample lock up points an lockers to leave your kit (2€ coin required).