The Internal Frame vs. External Frames packs debate
On a recent visit to a very busy hiking and camping store, a friend and I were lucky to be there at a time when the store wasn't busy and had a chance to speak to one of the salespeople. After doing so, he and I were more convinced than ever that for scouting and general backpacking, an external frame, (EF), pack is the way to go. The sales person explained the difference to us like this: Internal frame, (IF), packs are made more for off-trail use and mountaineering. Why? Because since you are off trail, you are going to be moving your body in ways so as to avoid obstacles like trees, ice ledges and who knows what. Internal frame packs fit right up against the back, and are made to flex along with your body. Sounds pretty good, huh? Well there's a trade-off! Internal frame packs put more weight on the shoulders as opposed to putting it on the waist. For those of us who have ever had back trouble or for younger boys who are still growing, you might want to think about that very carefully before you run off and buy an internal.
By comparison, and external frame pack takes that weight and transfers nearly 100% of it to the hips, which are better suited to carrying the weight than the shoulders. The frame holds the pack a little farther away from the back, but gives you some air circulation between your back and the pack. OK, so external frame backs aren't as cool as internals, but out on the trail, I'm not into looking cool anyway! For Philmont or general backpacking, you are on established trails and there is very little, if any, off trail hiking.
For those of you about to purchase a pack, we recommend that you visit a quality outdoor equipment store. The better establishments will take the time to show you different styles and actually fit the pack to you, showing you how to adjust all the straps in the process. They will also have some sandbags and load the pack up with 30-40 lbs. and tell you to walk around the store and continue shopping for a while to see how it feels.
What is an External Frame Pack?
An EF pack is a design where the frame is fully exposed on the outside of the
pack, and the pack itself is attached to the sides of the frame using straps,
aluminum pins, or other methods. The frame material of choice is aluminum,
mainly due to its lightweight, though there are variations. Kelty basically
owns the external aluminum frame market for packs and they make several very
good ones with telescoping frames. The pack, straps, and hip belts are attached
to the frame using buckles slid through holes on the frame providing a maximum
amount of adjustability. There are a few other brands, such as Gregory Packs
that start with an aluminum frame, but then include plastic cross-members and
back panel to provide greater flexibility and comfort. I have seen Coleman Peak
1 pack frames constructed entirely of plastic, which provide a significant
amount of flexibility while walking. Over the last several years, we have seen
less and less of these "variations".
Aluminum frames are generally slightly curved in a gentle S-shape down the sides, with cross members attaching the two sides together. Some frame designs also utilize a "lip" or shelf on the bottom, which enables the pack to stand on it's own when put on the ground and provide greater protection against unknowingly losing a sleeping bag if it's not lashed securely to the frame. The frame generally separates the pack from the back by an inch or so. Since there is ample room for air to circulate between the back and pack, EF packs are generally considered to be "cooler" to carry in warm weather, with the minor downside being that their greater distance from the back can also make them marginally harder to balance on your back. Carrying your weight higher and closer to the back can easily mitigate this.
Some frames may also include a cross member that extends beyond the top of the pack. This "extension" can be used to lash extra equipment on top of the pack, or make it easier to remove the pack from your back by providing another grab point to lift the pack off your back. The downside of the frame extension is that it can get caught on trees and branches when traveling off-trail. Even on-trail, some trail maintainers frequently forget to clear enough headroom for trail hikers, which can increase your chances of hitting branches. And during rainy or snowy conditions, branches can be weighted down. A frame extension can give you a cold or frosty shower if branches are hanging low overhead. Once again, it's a trade-off. Do you want more options to attach gear on the outside and make it easier to remove the pack, or travel "more compactly"?
EF packs typically (though not always) have two main compartments, a number of outside pockets, and an open space below the pack where a sleeping bag can be lashed to the frame. There are variations of course, such as "travel packs", which allow hip belts and shoulder straps to be hidden and secured in a zippered sleeve, minimizing the amount of free straps hanging loose (which could get caught on baggage handling equipment, train door handles, or a variety of other obstructions).
What is an Internal Frame Pack?
An internal frame pack has a frame that is simply inside the pack. Frequently,
the "frame" is nothing more than two aluminum, plastic, fiberglass,
or composite "stays" that run vertically from the top to the bottom
of the pack. They provide the primary means of support for the shoulder straps
and hip belt, and some basic structure to hang the pack from. Some
manufacturers have also experimented with composite "panels" which
cover a portion of the back. A unique variation on the IF theme is the latest
North Face design which utilize a small metal frame on the outside of the pack,
but with a pack designed in the "internal frame" style. vauDe, a German
manufacturer, also makes an external frame pack in the internal frame design,
and it's very highly regarded.
So what is the IF pack style? An IF pack always includes a large integral compartment on the bottom for your sleeping bag. This provides greater protection from the weather (since the bag is actually inside the pack) and eliminates the chance the sleeping bag will be lost in the backcountry, or gouged/damaged while traveling through brush.
There are generally fewer pockets on the outside of an IF pack, but many more lash points to attach equipment. This is likely to compensate for the loss of lash points that might have been provided by an external frame. Often, extra pockets can be purchased separately, and are often fully detachable. Many IF packs also utilize "compression straps" designed to compress the pack if it is not fully loaded. Whereas the EF pack provides a rigid frame on which to hang the pack, IF pack structure is often provided by the gear inside the pack. If the pack is not fully loaded, the compression straps eliminate the extra space by compressing the entire load into a smaller, tighter package.
Since the sleeping bag compartment is integral with the pack itself, IF packs are larger in appearance and heavier in weight. Since the pack is carried right against the back, it is generally hotter to carry in the summer, but easier to balance. Regular users of IF packs may actually find these packs to be "over padded", and some designs allow the user to remove lumbar padding and other padding on the back. Others may find the padding an added benefit and comfort.
IF packs also carry lower on the back, which changes the balance and minimizes your chances of catching the top of the pack on branches. Manufacturers have incorporated a variety of design enhancements such as quick-wicking fabrics and "ribbed" padding designs to help in making the pack cooler to carry. And since the entire pack is carried against the back, there is a greater surface area involved in transferring weight between the pack and body. On EF packs, the weight is typically carried at only three to five points on the pack frame. With IF packs, you get a sense that the pack is "draped" over your body - almost as if you're carrying someone on your back.