I find I really drink a lot on rides, if going by what I read others do. That said, I use camelbak packs, and if it's going to be long, I freeze a bottle or two depending on bike capacity to refill the pack. I'm short, and have always hated reaching to grab and replace bottles on the move. As far as what I fill with, I don't like all the sugary sports drinks, and found that LMNT works for me, with one flavor I've come to like. I mix up at home, and usually throw a couple of packets in a pocket for more if needed.