Once in Paris, you can use the following map of the main cycling lanes, and you'll find information about cycling in Paris here.
If you are looking for some green, you can also use your bikes (or the Velib' bike sharing service, which is also available in Ivry) to reach the Bois de Vincennes (in 10 to 15 minutes, map with cycling paths here), or you can try one of the cycling paths along the rivers Seine and Marne nearby.
