kams as it down....You will be fine with two bottles. On a 45 mile ride that's all I go through. I usually don't stop at that distance (except for a nature break). I recommend skipping the first rest stop and riding to the second. The first ones are usually packed and don't have the good food. I'd take 2 snacks that you are used to eating in case the rest stops don't have anything you can eat. Maybe 2 granola bars/Clif bars/your favorite bar and a Gu/Clif Shot/energy gel that you use.