Ultimate Direction Endorfun $75
Weighing only 18 ounces empty, with a harness that can be adjusted to match your torso, the no-frills Endorfun (previous page; 96 fl. oz., 150 cu. in.) is ideal for any trail, whether you're running the Wasatch Front 100 or out for a post-work jaunt in the Sierra foothills. Even nicer than the reduced weight, though, is the vest design with its breathable mesh-lined shoulder straps and yoked suspension system. Chest pockets up front keep energy bars, sunglasses, or a can of grizzly-bear pepper spray within quick reach. This design mastery, however, makes our beef with the Endorfun all the more ironic: The bladder, which you fill by lifting a Velcro flap, requires extra care when closing or water leaks out the top. (The valve also oozes and spits if it isn't secured upright.) Still, this is the lightest system of its size we know of, so it's tough to quibble with the dribble.
Your buddies are trying to pass you and just ahead is a series of granite ledges you know only too well as the Stairway to Hell. This is no time to have your water bladder sloshing around on your back. The ultra-ergonomic Rocket (far left; 72 fl. oz., 100 cu. in.) is only three inches thick fully loaded, and the pack's unique baffled reservoir collapses as it empties, eliminating the splish-splash. A sternum strap and a removable waist belt cinch the pack to your back, while an insulating sleeve on the tube keeps the next sip cold. An oversize bite valve delivers ample agua. Slip a multitool, pump, tube, bagel, and a thin shell into the outer compartment and you're set for a Saturday epic. We wondered if the energy-gel-pack holster in front was really necessary, but it's easy to get used to the convenience, and lest we forget, the Rocket was made for singletrack mavens.
The North Face Reservoir Hog
If you need a pack for summiting backyard peaks or overnighting
at altitude before heading out for the real deal, The North Face and MSR have teamed up to provide you with the Reservoir Hog (second from left; 70 fl. oz., 1,342 cu. in.). This bulletproof number weighs 2 pounds, 10 ounces empty (that's light for a pack this size), yet because it's constructed from durable 210-denier ripstop nylon and boasts an aluminum stay, the Hog is stable even when crammed full of gear. Unfortunately, the durable MSR CloudLiner Bladder lacks any real insulation, so you won't want to carry it in the desert, but freezing isn't a problem because your body temperature warms the bladder--in cold weather simply blow the water out of the tube and back into the reservoir. Truly a backcountry-worthy system, the Hog is compatible with MSR's superior filters so you can pump that stagnant pool of mud bugs directly into your pack's bladder. Bottoms up.