Originally Posted by Machka

You need to drink approx. one 750 ml bottle of water and/or sports drink every 1 to 1.5 hours during the time period that you are out riding. This is the case in the spring, summer, fall, and winter. If it is particularly hot and windy, you might want to drink a little more, if it is cooler, you could probably get away with a little bit less. If you are really working hard, you might want more, if you are casually riding you could get away with a little bit less.

However, when it gets cold, getting enough to drink can be challenging because bottles freeze. Therefore, I drink before I go out ... I'll put away 750 mls of fruit juice or something. Then I plan to stop back at home or at a convenience store in about 1-2 hours where I drink another 750 mls of water, sports drink, fruit juice or whatever. I repeat that till I'm done the ride, and then as soon as I get in at the end I drink another 750 mls. That seems to work quite well.