What I do: Even though I have a bottle cage on both bikes, I use the camelback. I have the 100oz bladder for just water, and on a REALLY long ride, I have an additional 35oz to hang next to the big one to fill with gatorade (hangs in the CB bag from the same hook). What works for me is, the night before, if it's going to be a HOT day, fill the bladder half way with water, blow it the rest of the way up, lay it carefully in the freezer overnight...then in the morning, it's got a big chunk of ice that I fill the rest with water, and if I was lucky, the tube is not blocked and the cap can come off easily. On a couple of LONG rides (most of the day), I have filled both bladders and emptied them.