A properly-fitting backpack is an important investment. Take the time to find the right one before hitting the trail.
Carrying a backpack that doesn't fit properly is one of the biggest mistakes people make on the trail. It should be painfully obvious if this applies to you.
Just ask Demetri "Coup" Coupounas, president of GoLite. In 1994, he abandoned a trip on the Appalachian Trail because his hips were bleeding from the weight of his pack. Last summer, a decade later, he covered nearly 960 miles of alpine thru-hiking wearing a well-fitting pack and grew so fond of it that he named it "Wilson."
Backpacks cost anywhere from $100 to $500, so take the time to search for one that is well-made and made for you.
What to ask
Ask yourself how long and how frequently you will be carrying the pack. Are you a "minimalist" or a "kitchen sink" packer? Use the gear requirements for your longest trip as a guide for pack volume, since weight and price increase with cubic inches.
Ask the sales associate to take your torso and hip measurements, but remember that layers of clothing will affect the fit of a pack. Measurements are just a guide that a pack will be comfortable. Wear one around the store for 15 minutes to determine its fit and load transfer. Most stores will add bags of sand or beans to produce weight, but consdier bringing your own gear to create realistic weight in the pack.
Finally, ask yourself: Is the pack comfortable? Do the shoulder straps stay in place? Does it pinch, chafe or restrict? Does the harness cut off your circulation when you squat or reach? If it rubs you wrong, send it packing.
Shoulder straps: Your shoulders should carry 20 to 30 percent of the load. Most packs feature a floating harness with lateral sway to allow for different upper-body widths. The straps should anchor to the back panel approximately one inch from the top of each shoulder. The padding must wrap snugly around the curve of your shoulder and end level with your armpit, with the buckle approximately one hand width lower to avoid chafing.
Sternum strap: The sternum strap should lay two inches below the collarbone. It helps to stabilize the pack and should not restrict breathing.
Hipbelt: Your hips should act as a platform, carrying 70 to 80 percent of the load. The hipbelt should be centered from top to bottom on your hipbones. After cinching, there should be two to three inches of strap on each side of the buckle and the padded ends should not touch in front. Osprey now offers a heat-molding technology for their BioForm CM Hipbelts. The belt takes the shape of your hips, so you won't have to break it in on the trail. Visit www.ospreypacks.com for a full listing of certified dealers.
Frame style: Internal frame packs are ideal for harder terrain, off-trail hiking and sports requiring agility. The slimmer shape closely hugs your body for better balance and maneuverability. Internal packs are top loaded into one deep compartment, with the sleeping bag carried inside at the bottom.
External frames are ideal for kids, beginners or hikers with heavy loads on easy to moderate trails. The rigid frame will restrict your agility and cause you to walk stiffer, but they're easier to pack and offer more accessibility.