Dehydration causes headaches, low energy, stomach cramps, and all other sorts of bonking. Packing water is the best thing you can do for your stamina. Here's how.
Deuter Race X Air (deuterusa.com; $99)
Kiss the days of sweaty backs goodbye. With Deuter's proprietary Aircomfort Back System, a strong mesh parcel curves to your back while the pack is slightly suspended from your body. The airflow keeps you cool and dry, and the well-designed hip belt keeps the pack secure and stable. Plastic mesh shoulder straps initially gave me pause-I thought they would pinch or irritate-but they too kept sweat at bay without any discomfort. This is Deuter's smallest Race series pack, but there was ample room for enough gear for a longer day ride. The pack's hydration bladder comes with a twist top bite valve that takes a ride or two to get used to. After that, it's smooth sailing.
Gregory Dipsea (Gregorypacks.com; $59)
This slim, girlish pack (made specifically for women; the Diablo is the men's option) packs more of a punch than you expect. Despite its small profile, the Dipsea has room for a tube, pump, food, rain shell, and sunscreen-it's a worthy mountain biking partner. Sporting the company's "bio-sync suspension," the Dipsea's shoulder and waist straps are elasticized where they attach to the pack body, which allows it to move with you. My main gripe with the Dipsea is that it doesn't come with a hydration bladder; my personal one was so big I had to fold it in half. Come on, Gregory - hook a consumer up.
Hydrapak Morro (hydrapak.com; $109)
If Hydrapak paid any more attention to detail on this pack you would swear it was custom made. The Morro has an the innovative twist closure on the bite valve hose, Hydrapak's new Quantum clip attachment system that keeps the hose close to the shoulder straps with an integrated magnet, and a fully reversible bladder so you can actually get it clean. The pack itself feels featherweight. It's got plenty of room for extra food and clothes for long rides but cleanly compresses down when it's emptier. This is a great pack at an excellent value.
Mountain Hardwear Fluid 10 (mountainhardwear.com; $80)
This super light daypack looks simple, but its technical features and smart storage design render it completely high tech. The OTF compression (On-The-Fly) relies on strategically placed straps to adjust load stability without girdling the pack, and the HardWave frame sheet incorporates a corrugated back panel that forms to your body, flattening the back panel without stiffness. A multitude of pockets continue to reveal themselves just when you need them; there's the fleece-lined sunglass stash, the zippered mesh pockets on the hip belt, the stretch side pockets and an internal zip pocket. Like the Gregory, this one doesn't include a hydration bladder.
Osprey Raptor 10 (ospreypacks.com; $89)
Osprey packs consistently impress me with their suspension, comfort, and fit, and the Raptor 10 is no exception. This pack looks sleek-small, even-but it's got room for the food, gear and clothes an all-day ride demands, intelligently placed pockets and straps that stay put. All this on a semi-rigid frame that moves with your body. Better yet, Osprey's HydraLock system pressurizes the water reservoir, increasing water flow. Turn the bite valve 90 degrees, bite, and the hose does the rest of the work. That's a beautiful thing when schlepping up five miles of single track under a blazing sun.