From the Bergan to the Modern Technical Pack
Rucksacks have evolved from relatively simple load carriers into highly specialised pieces of equipment designed around specific activities.
Walking, running, cycling, skiing, mountaineering and expedition travel all impose different demands on the wearer. As a result, modern packs have become increasingly specialised in the way they carry weight, stabilise a load, allow freedom of movement and provide access to equipment.
Yet almost every modern rucksack is still trying to solve the same basic problem:
How do you carry a load comfortably while allowing the human body to move efficiently?
From a bag with straps to a carrying system
Humans have carried loads on their backs for thousands of years, using wooden frames, baskets, hides and simple fabric sacks.
What distinguishes the modern rucksack is the deliberate attempt to transfer and stabilise the load through a structured carrying system rather than simply hanging it from the shoulders.
A particularly important development occurred in Norway in 1908.
Ole F. Bergan reportedly became dissatisfied with the way his hunting rucksack rubbed against his back. His first solution was to bend a juniper branch to form a support. He subsequently developed a tubular steel frame with leather straps and patented the design in 1909.
The first Bergans leather rucksack entered production shortly afterwards.
The concept was enormously influential and helped establish the external-frame rucksack.
External frames had several advantages. They separated the load from the wearer’s back, allowed airflow and provided a structure through which some of the load could be transferred towards the pelvis.
For carrying heavy loads over relatively straightforward terrain they worked extremely well.
However, they were less satisfactory when climbing, scrambling or skiing.
A load positioned away from the spine creates greater leverage over the body. The pack can also move independently of the wearer.
That problem contributed to another major development.
The internal-frame revolution
In 1967 American climber Greg Lowe designed the Lowe Alpine Expedition pack.
Instead of attaching a bag to a rigid external frame, Lowe incorporated the structural support inside the rucksack.
This allowed the pack to sit considerably closer to the body.
The design also incorporated features such as compression straps and load stabilisation which became fundamental to modern technical packs.
The principle remains important today.
A well-designed rucksack attempts to position the load:
close to the spine,
close to the body’s natural centre of gravity,
and securely enough that the pack moves with the wearer rather than independently of them.
From that principle, many specialist types of rucksack have evolved.
Trekking Day Bags
The traditional daysack remains perhaps the most familiar form of rucksack.
Most walking daypacks fall somewhere between approximately 15 and 35 litres, although larger packs may be useful in winter or where additional technical equipment is required.
Their purpose is straightforward: carry everything required for a day in the hills without the bulk and weight associated with an overnight trekking pack.
A typical hillwalking load might include:
waterproof clothing,
insulation,
food,
water,
navigation equipment,
first-aid equipment,
emergency equipment,
headtorch,
and possibly trekking poles.
Modern walking daypacks broadly follow two approaches to back-system design.
Some use a close-fitting padded back panel. These provide excellent stability and tend to work well when scrambling or travelling over uneven terrain.
Others use tensioned mesh systems which suspend the main body of the pack away from the back.
This creates airflow between the wearer and the pack and can significantly improve ventilation in warm conditions.
Modern packs also tend to provide much better access to equipment.
Large stretch front pockets, side bottle pockets, hip-belt pockets and hydration systems allow commonly used items to be reached quickly without completely unpacking the rucksack.
Current examples include packs such as the Osprey Talon 22, Deuter AC Lite series, Gregory Zulu range and similar walking packs from Lowe Alpine, Rab and Fjällräven.
Sport-Specific Backpacks
Perhaps the most significant development in modern rucksack design has been specialisation.
The important question is no longer simply:
“How large a rucksack do I need?”
Increasingly it is:
“What activity will I be doing while wearing it?”
A pack designed for running may be almost useless for carrying an expedition load.
A comfortable trekking rucksack may be completely unsuitable for technical climbing.
A ski touring pack requires features that a normal walking pack simply does not need.
Running Packs and Running Vests
Running exposes one of the fundamental weaknesses of a conventional rucksack.
It bounces.
During walking, a small amount of movement may be relatively insignificant.
During running, however, the same movement occurs thousands of times.
Running packs therefore evolved towards a design that wraps around the upper torso.
Many modern examples are now described as running vests rather than rucksacks.
Wide stretch shoulder sections replace conventional narrow straps.
Storage extends around the chest and ribs, allowing equipment to be distributed around the body rather than concentrated behind it.
Water bottles or soft flasks are commonly positioned on the front of the shoulder straps.
This allows the runner to drink without removing the pack.
Hands-free hydration systems also played an important role in this development.
CamelBak traces its origins to 1989 when a hands-free hydration system was developed for cycling.
The same principle was subsequently adopted widely in running and endurance sports.
Modern running packs may weigh only a few hundred grams while carrying:
water,
food,
waterproof clothing,
emergency equipment,
running poles,
a mobile phone,
and compulsory race equipment.
Typical capacity ranges from approximately 2 to 15 litres, although larger fastpacking packs may extend towards 20 litres.
The Salomon ADV Skin and Active Skin ranges are good examples of the modern running-vest concept.
Cycling Backpacks
Cycling places the body in a forward-inclined position.
This changes the way a rucksack sits on the wearer.
A conventional walking pack may ride upwards towards the shoulders and neck while cycling.
Cycling packs are therefore generally shorter, narrower and closely stabilised against the back.
Hydration systems became particularly important in this category because they allowed riders to drink without stopping.
Modern cycling packs frequently include:
hydration reservoirs,
tool compartments,
pump storage,
helmet attachment systems,
reflective elements,
ventilated back panels,
and compartments for spare tubes and clothing.
Mountain-bike packs may also incorporate back protection.
At the opposite end of the spectrum, road and cross-country packs can be extremely minimal, sometimes consisting of little more than a hydration reservoir and harness.
Urban cycling has generated another distinct category: waterproof commuter packs with padded laptop compartments.
Ski and Ski-Touring Packs
Skiing places particularly demanding requirements on a backpack.
The pack must remain stable while the skier changes direction rapidly.
It may also need to carry:
skis,
poles,
ice axes,
crampons,
a helmet,
climbing skins,
and additional clothing.
Backcountry skiing introduces another requirement.
Avalanche rescue equipment must be immediately accessible.
Dedicated compartments are therefore commonly provided for a shovel and avalanche probe.
The development of avalanche airbag systems added another dimension to ski-pack design.
Research and experimentation during the 1970s led to the idea that increasing a person’s effective volume could help them remain nearer the surface of moving avalanche debris.
Commercial avalanche airbag systems began appearing during the 1980s.
Modern systems may use compressed gas or electrically powered fans.
This means that some ski packs are no longer simply carrying devices.
They form part of the user’s avalanche safety equipment.
Typical ski-touring packs range from approximately 20 to 40 litres.
Current examples include technical packs from Ortovox, Osprey, Gregory, Deuter, Black Diamond and Simond.
Alpine Rucksacks
Alpine rucksacks place stability and freedom of movement above almost everything else.
On steep snow, ice or rock, a pack that moves independently of the climber can affect balance.
Alpine packs therefore tend to be:
tall,
narrow,
close fitting,
and relatively minimalist.
Anything likely to catch against rock or interfere with a climbing harness is reduced or removed.
Many alpine packs incorporate:
ice-axe attachments,
rope carrying systems,
compression straps,
reinforced crampon areas,
hydration compatibility,
and removable components.
Hip belts are often narrower and less heavily padded than those found on trekking packs.
This prevents them interfering with a climbing harness.
Some packs allow the lid, internal frame sheet, aluminium stay or hip-belt padding to be removed.
This allows the pack to be stripped down for summit attempts or fast-and-light climbing.
Approximately 30 to 50 litres covers much of modern alpinism.
A 30–35 litre pack may be suitable for technical day climbing.
Around 40 litres is a useful general alpine capacity.
Approximately 45–55 litres provides additional room for bivouac equipment, hut approaches or longer routes.
Current examples include packs such as the Simond Mountaineering 40, Black Diamond technical climbing packs, Blue Ice alpine packs and models from Rab, Montane and Osprey.
Trekking Rucksacks
Where alpine packs prioritise unrestricted movement, trekking rucksacks prioritise sustained load carriage.
When carrying equipment for several days, comfort becomes increasingly important.
A proper trekking pack usually has:
a substantial hip belt,
a rigid or semi-rigid internal frame,
a shaped shoulder harness,
load-lifter straps,
compression straps,
and an adjustable back length.
The hip belt is particularly important.
The pelvis is much better suited to carrying sustained weight than the shoulders alone.
A properly adjusted trekking pack transfers a significant proportion of the load onto the hips while the shoulder straps primarily stabilise the pack.
Load-lifter straps help pull the upper portion of the rucksack towards the body.
Modern trekking packs also offer considerably better access than traditional top-loading designs.
Many now provide:
front access,
side access,
lower compartment access,
large stretch pockets,
and multiple external storage areas.
Dedicated sleeping-bag compartments remain common on larger designs.
For lightweight multi-day trekking, around 45–55 litres may be sufficient.
For conventional backpacking, approximately 55–70 litres remains a useful range.
Equipment has also become lighter and more compressible.
Modern tents, sleeping bags, sleeping mats and clothing often allow travellers to use smaller packs than would previously have been necessary.
Current examples include the Lowe Alpine Sirac, Osprey Atmos and Aether ranges, Gregory Baltoro and Zulu packs, Deuter trekking packs and Fjällräven models.
Expedition Rucksacks
At the largest end of the spectrum sits the expedition rucksack.
These are effectively the heavy-haul vehicles of the backpack world.
Capacity typically begins around 70 litres and may extend beyond 100 litres.
Expedition climbers and remote travellers may need to carry:
large quantities of food,
fuel,
climbing equipment,
extreme-cold-weather clothing,
sleeping systems,
technical hardware,
and group equipment.
Although weight reduction remains desirable, structural strength becomes increasingly important.
The frame must prevent a heavy load collapsing away from the body.
The hip belt must transfer considerable weight to the pelvis.
Buckles, straps and fabrics must withstand prolonged abuse.
The larger the rucksack, however, the greater the temptation to fill it.
A 100-litre pack can easily encourage its owner to carry 100 litres of equipment regardless of whether every item is genuinely necessary.
For that reason, one of the most important principles of expedition packing is:
Before choosing a larger rucksack, first ask whether the load itself can be reduced.
Sometimes it cannot.
That is when an expedition pack becomes essential.
Current examples include the Osprey Aether Plus 85, Lowe Alpine Cerro Torre 80:100 and large expedition packs from Gregory, Fjällräven and other specialist manufacturers.
The Modern Rucksack Market
| Type | Typical capacity | Main design priority |
| Running vest | 2–15 L | Minimal bounce and immediate access |
| Cycling pack | 4–25 L | Hydration and stability |
| Trekking daypack | 15–35 L | Comfort, ventilation and accessibility |
| Ski touring | 20–40 L | Stability, ski carry and avalanche equipment |
| Alpine | 30–50 L | Close fit, low weight and climbing compatibility |
| Trekking | 45–70 L | Sustained load carriage and comfort |
| Expedition | 70–100+ L | Heavy-load carrying and durability |
Choosing the Right Rucksack
Capacity remains important, but volume alone tells only part of the story.
Two 40-litre rucksacks can be completely different pieces of equipment.
A 40-litre trekking sack may have a substantial padded hip belt and ventilated back system.
A 40-litre alpine pack may have minimal padding and a narrow profile designed to allow unrestricted movement while climbing.
A ski pack of the same volume may have reinforced ski attachments and avalanche equipment compartments.
The better question is therefore not:
“What size pack do I need?”
but:
“What do I need the pack to do?”
The fundamental principles of rucksack design have changed surprisingly little.
A pack must fit the wearer.
Heavy equipment should be controlled close to the body.
The pelvis should carry much of the load in larger packs.
Compression should prevent equipment shifting.
And the back system should match both the user’s anatomy and the activity being undertaken.
What has changed dramatically is the degree of specialisation.
A runner, cyclist, skier, alpinist, trekker and expedition mountaineer may all carry similar basic essentials.
But the way each person moves is very different.
Modern rucksack design has evolved around those differences.
The rucksack is no longer simply a bag carried on the back.
It is part of the equipment system connecting the load to the person carrying it.
