What sort of distances are you talking about Noel?
I think you can train yourself to manage on almost anything, its probably a good idea to experiment with different things.
I try and stick with everyday food, so bananas and a ham sandwich, especially for longer spins. Water with some mi-wadi through it. I find too much sugar a bit sickly.
As Kev says you can go from feeling great to bonking in minutes, having a granola bar or soemthing like that is a good idea