Buying a Backpack
Choose between internal or external frame
Beginning Backpackers who are shopping for their first pack must choose between two styles of backpacks:
external frame packs,
which have an exposed aluminum frame with the pack attached by straps and buckles or pins, and
internal frame packs,
which have the aluminum or plastic frame support inserted inside the pack, hidden from view.
Internal frame packs are the more popular backpack style, at least in the US. The advantage of internal frame packs is that the pack lays flush against your back via a large padded contour shell.
The pack basically wraps around your back so that the weight within the pack is transferred over a large surface area rather than by a few pressure points. (at shoulders and waist).
The padded shell and the transfer over larger surface area make internal frame packs more comfortable to wear than external frame packs.
Most internal frame packs have a large tube where the bulk of your gear is carried, with a lower compartment for your sleeping bag. The pack contents have a better chance of staying dry in rainy weather since it is all carried internally. (A wet sleeping bag is big trouble on a backpacking trip).
Since the internal frame pack wraps against your back and is flexible, the wearer has greater agility on rocky trails and steep slopes or when crossing streams trying to maintain stability against a fast current. Cross Country skiers and Rock Climbers almost exclusively use internal frame packs because of the better stability and agility they have than when wearing external frame packs.
Internal frame backs usually have several zippered pouches on the outside of the pack to carry things that might be needed during the day, preventing the need from unloading the pack innards in the tube to find an item.
With all these good common sense benefits of using an Internal frame pack, you may wonder why anyone would consider getting an external frame pack.
Actually, there are a couple of benefits of external frame packs. One is that they tend to be lighter than internal frame packs because they have less padding for the contours of your back. Another is than since there is about an inch separation between the frame and the pack, external frame backs allow for some air circulation and so can be cooler to carry, which might be a consideration if you expect to backpack in hot weather. (carrying an internal frame pack in hot weather almost always leaves you with a very sweaty back).
In an October 1, 1997 article, Kristen Hostetter of Backpacker Magazine wrote the following about external frame backpacks:
When I returned to solo backpacking after many years of doing short hikes and nature walks with my two daughters, I first used a classic rigid frame external backpack. The pack was indeed very light. I found I had to carefully rope my extra gear on the pack frame, which was not a huge problem, but it did take extra time. I just had to make sure all the items were secure so as as not to have anything drop off without my knowledge.
The biggest downside of the pack I used was the fewer pressure points for the weight - which would eventually make my shoulders and lower back begin to feel a little sore. On one particularly long hike (eleven miles), I actually received some sores on my sides of my waist where the frame of the pack rubbed.
Some of the newer external pack designs have abandoned the old rigid frame - their frames have some moveable items that bend with your step slightly, like the internal packs do.
Many backpackers are convinced that despite being more awkward to carry that internal frame backs, they carry a heavy load better than internal frame backs. A backpacker in the message forum stated the following about external frame packs:
There are many good websites with more detail about internal and external packs.
Outdoorreview.com is a good site to visit because it contains numerous reviews of packs. This is extremely valuable because it is very hard to know much about a pack until you have taken it out on a couple of trips. Reviews by people who have bought and used different pack models is good as gold, and better than most of what a store salesman might tell you.
(update May, 2001 - I picked up a Kelty Tioga external frame pack and probably will never go back to my internal frame for long trips. The Kelty pack carrys my load higher - making it easier to haul a lot of gear. The main reason I like it is I walk more upright with this kind of pack, rather than slightly hunched over with my internal frame. - J.Ratzloff)