Stuff It!: The basics for picking the right backpack

By John Million

I know the look well. Head back, slack jawed, glazed eyes scanning wildly across the massive block of backpacks stretched along one full wall of the outdoor gear shop. Internal, external, day packs, rucksacks, front load, top load, kid carriers, dog packs, fanny packs, travel packs, it’s all too much. Fear not, with some basic information, even a novice can face that threatening expanse and come out hiking!

Let’s assume that you need a pack that will allow you to go out for multi-day trips and you are based in the Northeast. We have already narrowed our search. The first big decision is to get an external or internal frame pack. Both have advantages and the type of trips you most often take will help you decide. For a three-day trip, you will need a 3000-3500 cubic inch external frame or a 4000-4500 cubic inch internal frame pack.

External vs. Internal Frames
External frame packs have a sack mounted on a rigid frame of aluminum or plastic polymer. Shoulder straps and a hip belt support the load, and a back band keeps the pack slightly away from your body. External frames are good choices for hikes on established trails in moderate terrain. They can carry a great deal of gear, have many pockets for organization, and are generally cooler as the back band provides ventilation between the load and your back.

External frames are usually less expensive than comparably sized internal frames. They also are heavier and bulkier and the load may shift from side to side on rough terrain or during activities such as skiing or climbing. External packs usually have a divided sack that allows for top loading the upper area and packing the easily accessible lower panel section with more often used items. The sleeping bag is strapped on the bottom of the frame.

Internal frames fit snugly against your back and bring the weight closer to your natural center of gravity. This gives the upper body greater freedom of movement and helps you maintain balance in challenging terrain or during active sports. An internal frame of aluminum or plastic in a parallel or V-shaped configuration supports the load. A sheet of high density plastic protects the back and an integrated suspension system of shoulder and hip belts, and sternum and load stabilizer straps, allow for adjustability of fit and comfort.

Internal frame packs are more streamlined and provide easier passage through tight spots and when bushwhacking. They also need to be packed carefully for proper weight distribution and gear access. They can be warmer due to less ventilation as the load rests directly on the back and can be more expensive than an external frame pack. Top loading packs will have greater capacity and panel loaders will allow easier access but have to be laid down to be opened. In either case, your sleeping bag is tucked inside the pack.

The Right Size
Just as the wrong size boots can make you miserable, a poor fitting pack can quickly ruin a trip. Buying the correct size pack is critical to achieving a good fit and bearing your load comfortably. Many people do not realize that backpacks have sizes, even fewer know how to measure for one. Most pack frames are sized by torso length, or the measure from the vertebra between the tops of the shoulder blades to the top of the hip bone (iliac crest). Torso length does not always correspond to height. For example, although I am six feet, five inches tall, my long legs provide me with a torso length for a size medium pack frame. Most outdoor specialty stores will be willing to measure you for proper size.

Does it Fit?
Both types of packs rely on the hip belt to carry approximately 75 percent of the weight load. A good hip belt will be soft and conforming foam on the inside with a stiffer material for support on the outside. The belt should rest cupping the weight over the tops of the hip bones. The remaining 25 percent of the load is primarily borne by the shoulder straps. Again, soft but supportive padding will be much appreciated as the miles add up on the trail.

External frame packs can usually be size adjusted by removing clevis pins in the pack frame tubing, extending the tubing to a longer length, and replacing the pins. This ease of adjustability make external frames a good choice for growing children or for packs that will be used by multiple individuals. When properly fitted, the shoulder straps on an external frame pack will be level with or slightly above the shoulder. The back band should be tight and positioned at mid-back for maximum comfort, and the hip belt should ride easily on the pelvis.

Internal frame packs vary by vendor but most have a shoulder yoke suspension system that attaches to the frame in the middle of the back. This yoke can be adjusted for fit by a sliding track, straps of webbing, or hook and loop Velcro type systems. When fitted correctly, the shoulder straps will wrap around the shoulder without gaps and curve down to the yoke attachment. The bottom of the strap padding should be about a hand width below your armpit. The lumbar pad should rest in the hollow of your back and the hip belts should ride on the iliac crest.

When fitting a pack, begin with no weight in the pack. Start with the hip belt, move up to the shoulder straps, and then make adjustments to fine tune. Many packs now have load stabilizer straps that will allow you to alter the amount of weight the shoulder straps bear. Sternum straps keep the shoulder straps from sliding and help the yoke stay snug. After filling the pack with moderate weight, take your time and walk around the store to find out how the pack feels, note any areas of discomfort, and see how the load rides for stability and weight distribution. Like a good pair of boots, when you do not feel anything but solid support, you have found the right fit.

John Million is ADK's deputy executive director. The above information was adapted from an article in Adirondac.