Hont said:
The question was when is it too late to eat on a ride? The half hour question was an example really.
Looking for when is the latest it's worth eating.
Well it all depends on the length of the ride, for example i did a 50 mile ride today, didn't need to eat anything, just drank plain old water. if that milage increases though i'll take a gel or maybe even peanut butter and jam sandwiches. It also changes with different people, there is no way we can tell you when to eat because it's impossible. Just experiment with different methods, times and foods till you find the right one.
As a bench mark though i'd say eat an hour before you are likely to feel a drop in energy. Half an hour is fairly pointless.