I should mention that I ride with people who put Hammer Recoverite in one water bottle and do very well on it. Recoverite is 3 carbs/1 protein. I use 7:1 for my malto/whey mix, but I know an LD racer who uses Endurox, a 4:1 carb/protein recovery drink in a Camelbak and has set records using it. He's tried my homebrew and says it's too wimpy for him.

Everyone is different. Experiment and use what works for you. If you go out with only water and get dizzy after 45 minutes, maybe you need some calories.