The problem could be something other than what you might think. Obviously, since you carry the gels and one bottle of sport drink you are aware of the need for eating and hydration on the bike. Usually any distance more than 40-50 miles you have to eat something.

One big problem might be acid/alkaline balance. When you exercise it creates a lot of acid metabolytes in the body. These need to be flushed out with lots of water. Preferably with an alkaline PH. Most sports drinks and gels and energy bars are acidic to the body so even though they give you energy they effect overall body PH in a negative way. This is my guess part of the problem that many cyclists experience when eating on the bike.

Here are some possible suggestions. If you can afford a water ionizer/alkalinizer machine buy one and use it to drink and fill your bottles.

Instead of gatorade or powerade see if there are any of the higher quality sports drinks like Heed that have a PH higher than 7.5. I don't know if they do I haven't researched any yet.

Try some green powder, a little soy protein, and a few drops of Stevia as an alternate sports drink. This is a lot more healthy and less acidic than sports drink and is full of anti-oxididents which you need during exercise.

Instead of gels and cliff bars. Take some raw carrots and other raw vegetables that can keep for few hours in a small zip-lock baggy. Eat these instead of the other processed energy foods. Veggies are alkaline and will help balance your bodies acid production during exercise. Probably best if you take the high calorie kind of veggies like carrots and raw peas. YOu can just run frozen peas under warm water in a collander to unfreeze them. Also, try some almonds. And celery is the ideal food for getting your electrolytes back it's high in sodium and potassium.