We are a group of 11 (3 families) day tripping from Paris. Looks fun to rent bikes, ride to Fontainbleu for chateau tour, and then ride through forest to Barbizon. There is an outfit that offers a tour guide: FONTAINEBLEAU BIKE HIRE & TOURS. Has anyone done this? I'm not seeing any reviews online. Do we need a tour guide? Can we do this on our own, just renting bikes, with no guided tour? Thanks in advance for any guidance/advice.