There are a few simple decisions that need to be made in order to choose what kind of pack you need for your trips. These determinations will help to guide you in finding the category of pack you want, and ultimately making a decision about which one you want to get. First you need to ask yourself what sort of trip do you like to take, or if you are preparing for one specifictrip, what kind of trip is it? Determining the sort of trips will tell you what kind of pack you need.
Extended trips. These types of packs usually are 4,000 cubic inches or bigger. They will havereally good suspension systems. These packs are the best at transferring heavy loads through their hip belt, but they are also the largest and heaviest. Usually used on trips that will be more than one week.
Extended weekend. These packs are between 2,000-4,000 cubic inches. This is also the most popular category. options in this category can range from approximately 12 oz-about 4 lbs, and range in suspension from multiple metal stays and a frame sheet, to having no suspension. Because this category varies so widely you will want to know what feature is most important to you (weight, comfort, pockets, etc.)
Technical daypacks. These packs are smaller packs, that at the largest might hold enough for an overnight, but are generally for day hikes, not for carrying tents and sleeping bags. These offer all sorts of features, they are often specialized for specialized activities like mountaineering but there are also some that are designed just for going around town.
Hydration packs. These packs are made for the sole purpose of bringing water with you. They are fitted with a bladder and a hose system to give you hands free drinking while you are hiking or biking. These generally only have enough room for a couple pieces of gear.
Now you need to choose what is most important to you. Packs are separated into categoriesbased on the features they have:
Minimalist. These packs sacrifice anything to save on weight. Their goal is the faster and lighter the better. This is not the pack you should get if you are carrying a big load or love bringing lots of gear. These are the packs to get if you think one the handle on your toothbrush and the label on your peanut butter are too heavy to bring.
Ultralight. This means you like saving weight, you’ll give up a few things to get it down, but you still like some suspension, and maybe a daisy chain too.
Lightweight. These packs are the largest category, and offer a host of options. They use many lightweight technologies, but give up basically no features, and make few design changes to accomplish weight savings.
Super packer. Super packers are huge and heavy, they are for people who believe that roughing it is nothing. They believe that comfort is number one, and they will bring 2 of everything. These packs offer tonsof space and padding and suspension to boot. Howeverit comes at the price of weight and speed.
Once you have chosen what you need in a pack, you need to decide what you want in a pack. You need to test some alternatives, and look at different features too. For example, some packs offer exceptionally good ventilation, others exceptionally good compression. See if you prefer external pockets or not. Discover just how much you want to pay. And above all, make sure it fits well.