Bring it all along in Osprey's Viper 13 pack. The triple ripstop polyester material is durable enough to haul large loads day in and day out. Its 3 liter Hydraulics Reservoir allows you to ride for hours without refilling. For storage, there is an internal tool organizer, a sunglass pocket, a large front pocket, and Osprey's LidLock helmet clip. Plus you can stash layers in the front and mesh side pockets for easy retrieval. Other features that will have you singing this pack's praise include a comfy BioStretch harness, a webbed hipbelt, a ventilated back panel, and a magnetic bite valve attachment that stays put no matter how rough the trail gets.
Viper and Verve Series ~ Osprey Hydraulics
Osprey LidLock Tech Video