I tend to dehydrate easily and so I always carry at least one, and usually two bottles, one of FRS and one of plain water and then carry extra tubes of FRS powder. On longer rides I can stop and refill the bottles. On Hot and Humid days here in Texas, about 60% of the time, I can go through a bottle an hour and still end up so dry I'm nearly unable toswallow at the end of the ride. It all depends on the weather, but I believe that water is easily carried and important to drink.

marni