It's been a while but I biked in and out from CDG airport; not a good experience. I would not do it again and I've traveled many roads with heavy traffic. I've also cycled extensPerhaps you can find a good route though; I couldn't. That said, the cycling in France, once you get out of the greater Paris area, is absolutely first rate. There is a fine road network that is well signed and maps are easy to come by. I prefer by and large areas south of where you are going but Alsace Lorraine and the Franche Comte are very beautiful.