I totally went out of gas 20 km into my ride today. fortunately there was a convenience store right there. stopped to buy an isotonic drink. after that i was alright. not a very good feeling though.. keeping food down while riding is not easy. but u need it.. so its quite a catch 22. u eat just enough to keep it down but u need to do it so often and like my friends say 'u just fart and its gone'