You may call them Packs, backpacks, Haver-Sacks, Rug Sacks, Nap Sacks or summit bags etc may come with different features and sizes. You may select one or more of them as part of your outdoor gear depending upon your utility and use.
Generally if you are going for an out-door camping which takes more than a day it is advisable to carry two bags one full-size back pack to carry your gear for camping and in the other a day pack that you will utilize once you are near your base camp. All packs should allow you to carry weight close to your body and to centre the load over your hips and legs.
Bags generally come with frames which may be either internal or external. A rigid frame within the pack helps it maintain its shape and bug your back, assisting you in keeping your balance as your climb, walk or scramble. When you shoulder an internal-frame pack, the weight is carried relatively low on your body, which is another plus for maintaining balance. A moderate drawback of this feature is that the weight is not carried high enough to be completely transferred to your hips. Instead, some burden must be carried by your shoulders and back. The body-hugging nature of internal-frame packs also make them somewhat uncomfortable in hot weather.
The volume of most internal-frame packs can be easily adjusted with compression straps, and this is a significant advantage for climbing. A full-size pack with internal frame can be used on the approach and then emptied of most items in the tent and then re-adjusted and transformed into a compact summit pack. The clean, narrow profile of internal frame pack will allow them to be taken through heavy brush or hauled up rock pitches with a minimum of snags.
External frame packs were once the only type of pack in use, but they now see only limited service. The pack contents are suspended from a ladder like frame, which is held away from the back by taut nylon back bands. External frame packs provide some advantages, like holding load high and transferring weight to hips and keep you cooler. Some climbers use them for long, easy approaches, carrying a small daypack inside for the summit day. But external frames have limitation when it comes to climbing steep slopes, they tend to shift without warning. The sudden movement of 20 KGs or so across shoulder blades can easily make you loose your balance.
While buying Backpacks factor what trip you are buying it for typically a overnight trip will require 40 liters of bags; but if you tent to go for more trek that last for 5 to 7 days or more you will require and 60 to 80 liters of bags. For a bigger expedition some times you may event require a bigger bag.
The most important objective while buying a bag is that it fits your body. The pack’s adjustment range must be compatible with you back length. Some packs adjust to a wide range of sizes; other doesn’t. Virtually no individual backpack provides a good fit for everyone, so don’t place all your faith in endorsements from any vendors. Try various packs and be your own judge.
Don’t be in a hurry when fitting a pack. Load it up, as you would on an actual climb or trek. Look in the mirror if it fits into your frame properly also if the internal frame matches the shape of your back.
Loosen all the adjustment straps before putting the pack on, then tighten in the order recommended in manual. Check yourself in a mirror or ask someone, to see if the frame correctly follows your back. If it doesn’t, check whether the frame can be reshaped to match your back. The shoulder strap should attach to the pack 2 or 3 inches below the crest of your shoulders and leave little or not gap behind your back.
Once the pack is adjusted to your liking, check the clearance. Can you look up without hitting your head on the frame or top packet? Can you look up as if you were wearing a helmet? Next, check for adequate padding wherever the pack touches your body. Pay particular attention to the thickness and quality of padding used in the shoulder straps and hip belt. The hip belt should be substantial; its padding should cover the hip bones by good margins. For proper load transfer to the hips, ensure that the hip belt wraps directly onto the top of your hip bones, not around the sides of the hip bones or around the waist.
Other things to check in backpack
· How is the suspension system designed? Does it look durable, or does it look like it could fail at weak spots?· How sturdy is the pack’s stitching?· Does the pack rely on zippers to retain the contents? If the zippers fail, can you still use the pack?· How convenient is it to store, arrange, and access your gear in the pack?· Does the pack provide means of carrying special items shovels, walking stick, sleeping mats, carabineers etc.· Does the pack have a haul loops and ice axe loops?· Are there compression straps to redue the pack’s volume or to prevent the load from shifting while climbing or scrambling?· It there a means of increasing the pack’s capacity for extended trips, such as an expandable collar with a gloating top pocket or separate side pocket accessories?· Does the pack have a sterum straps to help prevent the pack from shifting on difficult terrains?· Does the pack have a smooth profile, or will it get tangled during bushwhacks through thick outgrowth in forest?
Quick Check list while buying backpacks
· Size and frame to match your requirement and body respectively· 2 inches of buckle· 4 inches wide padding where it cover hips· Adjustable straps (Compression straps)· Loops and straps for Ice Axe, Walking Sticks, Mats etc· Pockets on top and back for maps; first aid, wallets etc· Space for hydration pack· Strength of material and stitching
Note: Also buy a bag cover made of water proof nylon; this will protect your bag from rain, dust and bushes.
Tips on packing
Strategically loading the items in your internal-frame pack can dramatically influence your speed, endurance, and enjoyment of an out-going. Generally, you will feel best if you can concentrate the load on your hips and avoid loading your back and shoulders. But now as per some experts it is also recommended to add some part of the heavy load just near shoulder. But all heavy load should be closer to your body and light load can be at the bottom; top and away from the body.
The lightest and fluffiest arcicles (sleeping bags and extra closing) in the bottom; place the densest items (water, food, stove fuel, rope) up top, near the shoulder blades.
For more difficult terrain, revise your trail-packing strategy. Pack the heavy items slightly lower, and ensure they are as close to the back as possible. This will force more load onto your back and shoulder but will lower your centre of gravity and allow you to more easily keep your balance.
Along with arranging items in your pack for optimum weight distribution, organize them for quick access. Articles like gloves, hats, sunglasses, maps and insect repellent, which are sometimes need to a moment’s notice, are ideally carried in side and top pockets.
Plan your strategy for keeping your pack dry in monsoon with Poncho and/or bag cover.