Pack Bag Volume
|Length of Trip ||External Frame |
(in3 [cu in] and Liters)
2-4 Days ||1,500+ in3 (25+ Liters) ||3,500-4,500 in3 (57+ L)
|5-7 Days ||2,000+ in3 (33+ Liters) ||4,500-6,000 in3 (73+ L)
|8-10 Days ||3,000+ in3 (39+ Liters) ||5,500+ in3 (90+ L)
REI recommends 40 L (2,400 in3) to 70 L (4,200 in3) for overnight trips.
I've done overnights with a 1,200 in3 daypack, but had a lot of stuff hanging from the outside.
My old (late 60's) external frame (kelty style) pack is 2,600 in3 in two main compartments, and has worked for 5 day hikes.
Plus 650 in3 in 5 external pockets.
External frame packs can be smaller than internal frame packs because there are spaces outside the packbag to strap large items directly to the frame.
Source: Buying a Backpack: Fitting Solutions for Every Frame at AMC
- Under 2,000 in3: Small packs for day trips like hiking and ski touring. They have no frame, a thin belt, and possibly a chest strap, and vary in the number of pockets and other features.
- 2,000 to 3,500 in3: Stream-lined packs for gear-intensive day trips like climbing and winter hiking. Most have a thin foam back pad, and straps to draw the pack against your hips (stabilizer straps) and upper back (load-lifters). The design is generally minimalist to reduce weight and bulk.
- 3,500 to 4,500 in3: For light packers on warm-weather weekend trips. If your gear is bulky, get a pack closer to 4,500 in3ches for weekend trips.
- 4,500 to 6,000 in3: Large enough for treks of up to a week, year-round. These popular packs vary greatly in design, features, and fit.
The Complete Walker IV has a formula for computing the correct size which is available at Backpacking-guide.com
It makes a big difference if you go alone or with a group and how warm you sleep. For example: Spring or Fall 3 day trip, 150 lb hiker:
The Complete Walker formula doesn't distinguish between internal or external frame packs, but since internal frame is preferred now I would guess it assumes all gear will fit inside.
|Cold sensitivity ||Number in group
|Solo ||2 ||3 ||≥4
|warm ||2805 ||1870 ||1309 ||1122
|normal ||4208 ||2805 ||1964 ||1683
|cold ||5611 ||3741 ||2618 ||2244
|winter trip |
|6734 ||4489 ||3142 ||2603
|6 day trip |
spring - normal
|5952 ||3968 ||2777 ||2380
According to Wayne Gregory, your correct frame size can be found by measuring your torso from the seventh vertebra down the spine to the point in the small of your back which is horizontally level with the top of your hip bones. To find this point, use your fingers to trace the hip bone upwards till you feel the point where the top edge of your hip bones curve inwards, on the side of the hip, creating something of a shelf. This measurement is the torso length, especially useful to consider those packs with non-adjustable back system. In fact this system that is used throughout the outdoor industry today to measure the exact body size and to determine the correct frame's size.
Source: rootball at WhiteBlaze.net/forum/
Measuring torso length at REI
Small - 16 - 18.5 in
Medium - 17.5 - 20.3 in
Large - 19 - 22.5 in
See: Backpacks: Finding Your Torso and Hip Size: Expert Advice from REI
Lowe Granite Gear
The Nov. 2010 Backpacker gave the Gregory Baltro 70 their editors choice hall of fame award.
Sierra Trading Post
Using your Backpack
How to Load a backpack:
The general rule is heaver items should be placed in the center and as close to your back as possible.
Usually higher up so with a slight forward bend you can center the load over your hips. For uneven steep or rocky trails you may want to put heavy items toward the bottom to lower your center of gravity.
I was getting in shape by tying heavy weights to the top of my external frame pack and when I made a slight slip on a rock in a stream crossing it pulled me in head first.
Usually the sleeping bag goes in the bottom compartment first along with whatever other small items you can fit around it. This acts as a foundation for the main compartment.
See packs at outdoorsMalaysia.blogspot.com
How much weight to cary:
15 - 25% of your body weight is a general rule.
On longer expeditions or winter trips this may go up to 1/3 of body weight.
Loosen all suspension straps. With the hipbelt resting atop your hipbones, pull the belt snug. Tighten the stabilizer straps connecting the belt to the pack's bottom.
Tighten shoulder straps so 70 - 80% of the weight is on your hips.
Next, tighten the load-lifters, which should should angle back toward the pack body at a 45-degree angle. Finally, tighten the shoulder and chest straps.
REI says "Gently snug the load-lifter straps to pull weight off your shoulders. (Over-tightening the load lifters will cause a gap to form between your shoulders and the shoulder straps.)"
Load Lifters: Tighten to pull the weight closer to your back for better control, and loosen them to allow the load to settle onto your hips for more comfortable striding.
On long ascents, loosen the hipbelt and stabilizer straps to increase mobility for hips and legs. When going downhill, retighten.
loosen shoulder straps to get load on hips
tighten load lifter so pack doesn't fall to far back at the shoulders
Tighten straps for more control.
loosen sternum strap widen straps to minimize pain around neck
tighten to pull in and relieve pressure on arm pits.
lumbar strap on hip belt- Minimal effect.
Video at Backpacker Magazine
Expert Advice from REI:
How to Choose a Backpack
Backpacks: Adjusting the Fit:
How to Hoist a Loaded Backpack
Hiking Backpacks - Making The Right Choice at Backpacking-guide.com
Backpacks and Backpack Reviews - Trailspace.com
packs at outdoorsMalaysia.blogspot.com
Find the right pack at AMC
Buying a Backpack: Fitting Solutions for Every Frame at AMC
How to Adjust a Backpack | eHow.com
BackpackGearTest.org - Packs
last updated 25 May 2011