I'm with Pamestique being mountain biker and road. Only use it on the road for longer rides where more than one bottle is required but it is so easy to continually sip from the Camelback that I do not get de-hydrated. Mine is just the basic one with just a small pocket with a zip so I will not get tempted to carry "Extra" tools or clothing to my normal rides. 1.5 litres of water will do me for a couple of hours on a hot ride and even up a long climb where reaching for the bottle may be put off for a while- the Camelback is used continually.