The Osprey Escapist is an all around multi-sport backpack designed to do it all.  Great medium capacity slim fitting design, well balanced with hipbelt to carry a decent load.  Easy access pockets for use while hiking or riding, features the airscape backpanel to keep you cool and ventilated and intergrated rain cover in case things get a bit wet!  This pack is compatible with and has the provisions to take an Osprey hydration bladder if you decide you need a little extra hydration on your treck.