In case anyone's interested, I asked my family doc last year whether we should bring some kind of sports drink mix on the Seattle to Portland ride. She's a super jock, champion mountain climber, and has done the STP on a tandem 8 times as part of the medical team. She said she once asked a guy she used to date, a doc who was on the US Olympic team nutrition committee, about what is really important to take in on a long ride. He said if you drink plenty of water and eat the stuff at the food stops like PBJ, bananas, oranges, bagels, boiled potato, you would have everything you need. Worked for us last year.

On my weekly 30 mile rides, I usually eat a Balance or Luna bar, and that's it, with lots of water. 60 mile rides, two bars and water.