Some things to consider
Studies relating performance to caffeine
cycling performance tips
For my personal experience, I like redbull or rockstar juiced before a ride, but it's by no means necessary. I don't know that I see that much of an enhancement other than a general increase in alertness.
oh, and I can't do coffee- it makes me have to pee too much, too often. Not fun when trying to do a long ride/stay properly hydrated. For some reason, caffeine pills, redbull and rockstar don't have this effect on me. hmm. :rolleyes: