Knottedyet gives perfect advice. Way to go!

Think of the rides with respect to time. When you go 50 miles, you are spending a lot of time doing cardio on your bike. Your body must have sustenence. You got some good advice from all of the posts, and the trick is to focus on liquid and nutrition as you increase your distance, to discover what works for you, because you are spending more "time" with a sustained high heart rate, and you are burning calories, electrolytes and water out of your body.

I can tell you what works for me, but keep in mind it might be different for you. I have two 28 oz water bottles filled with a fitness drink containing electrolytes and calories. On hot days I carry additional smaller bottles in my rear jersey pockets. I carry Clif Bloks (no caffeine) in a small handlebar pouch, and another backup package in my saddle pack. I carry fitness drink powder backup in my saddle pack also. I will carry a banana and some oreo cookies. All of that will get me through 50 miles.

I am careful to stay focused on my time and miles, and I stop to rest my rear off the saddle at certain intervals. I take this time to drink and eat. On the longer rides, in the last 10 miles, if I feel fatigue, that is when I really start popping the Clif Bloks, which is why they are easy for me to reach in the handlebar pouch.

When I get back to my starting point, which is usually my car at the State Park, I have a thermos of chocolate milk waiting for me as my recovery drink.

Mostly, though, you need more rides to figure this all out for your own body.

Darcy