Choosing a new backpack for a Scout backpacker is a critical and expensive decision so spend some time making it. Visit some stores and try on a few packs. See what your friends have and how they like it. Ask the trek leaders what they recommend. Then find (and buy) what you need.
In the meantime, borrow or rent a pack for your first few practice hikes or summer camp. There are tens of thousand of unused backpacks sitting in closets, basements, and garages for you to borrow. Just look for them. However, if you borrow a pack, make sure it gets re-adjusted it to fit your body. Otherwise you will have a bad experience.
Size is important. Most Scouts need a pack that can hold 50-70 liters of clothing and equipment for a one or two week backpacking trip (like Philmont). Do not go over or under this unless you have thought it thorough and have specific reasons. A pack that is too small will not hold all your stuff and you end up tying things onto the outside of the pack. Packs that are too large will get filled up with unnecessary items that just add weight.
Many hikers work too hard because they have not adjusted the straps on their backpack correctly. (Watch the video below to see how a pack should fit.) Always make sure you have at least 20 pounds of weight in the pack when trying it on in the store. (An empty backpack tells you almost nothing about how it fits when full.) And then walk around the store with the loaded backpack to see if there are any problems, like the pack pinching your shoulders. Try more than one pack before making a decision.
An important consideration with backpacks is the number of pockets or zippers on the back of the pack. Some guys like to put things like cat hole shovels, first aid kits, snacks, water tablets etc. in an outside pocket so they are easy to retrieve. Other guys like a sleek look and no pockets. Many new packs do not have pockets because zippers add weight, forcing the user to put everything inside the main cavity. Know what you like and need when selecting a pack.
There are two traditional types of backpacks for hikers that Scout leaders will talk about: the traditional external frame and the internal frame. However, external frames have evolved into hybrid internal frames with fortified frames. Many retail stores no longer carry traditional external frame packs and they may have to be ordered online. Ultralight packs are emerging as a popular third category, but they are often very similar to internal frame backpacks with lighter (or missing) frames.
Internal Frame Backpacks incorporate a plastic or metal frame into the fabric or interior of the backpack. (Basically they took the larger external frame, made it smaller by using stronger types of aluminum, and embedded the smaller frame into the fabric of the pack.) They might be more complicated to pack (sometimes having only one large cavity) but sit closer to the body (shoulders) creating better balance and easier clearance on overgrown trails. Internal frame packs are the most common pack you will see on the trail, partly because they can be lighter than external frame packs.
External Frame Backpacks were introduced decades ago using a metal tube frame upon which a fabric pack was attached, but they are increasingly rare among hikers today. In fact, many stores do not sell them anymore. External frames were easy to pack, lasted a long time, and allowed good weight disbursement over the hips and legs which means they allow young backpackers to handle awkward loads on most terrain. It is simple to tie things onto the outside of an external frame pack but that often means snagging the pack on trees and bushes. The frames eventually break and they can be dangerous if Scouts are throwing them around – like from a boat to the dock.
Ultralight Backpacks are a variation on internal frame backpacks. They are made of light material and are generally just a large cavity wrapped around a very basic frame (or no frame at all). Ultralight backpacks come in all sizes. While the largest ones might carry up to 30 lbs, they are generally designed to carry 20 pounds or less. Ultralight packs usually weigh less than two pounds empty.
When buying a pack, try on a “fully” loaded pack at the store. Take your time to insure proper fit. Be certain to work all of the pocket zippers. Make sure the hip strap fits and can be adjusted. Be sure the pack allows sufficient space and/or tie-downs to accommodate a sleeping bag, pad, and bear canister. Ask if the pack can be repaired by the manufacturer.
Your purchase should allow multiple adjustments to handle the expected growth of a young hiker’s torso. Also, a backpack should be refitted prior to any major trek because young bodies change over time.
A Waterproof Pack Cover is a common accessory, especially if you live in areas where it rains a lot. A waterproof pack cover needs to be large enough to protect items strapped to the exterior of the pack. A couple of large garbage bags may be suitable for summer hiking, but if multiple rainy days are anticipated (like at Philmont) a real pack cover is better. They cost up to $40, but are much more durable than garbage bags.
Some backpacks claim to be waterproof, but that is extremely rare. Lining the inside of a Scout backpack with a light-colored trash compactor bag helps keep everything dry and easy to find.
Watch this video to see how a pack should fit.
Remember to put the lightest stuff (like your sleeping bag) at the bottom of the pack and the heavy stuff (like food and water) at the top, close to your back and between your shoulder blades. When hiking, the weight of the pack and its contents should sit mostly on your hips and not on your shoulders.