(The Gear Loop) - The Hitchhiker's Guide to the Galaxy once perfectly stated: "If you want to survive out here, you've got to know where your towel is". While hiking or trekking might be on a slightly less galactic scale, there’s a bunch of essential gear that you’ll really, really want to find quickly at various points of the day.
From tent pegs to waterproofs, maps to crampons, head torches to water bottles, knowing where the essentials are is pretty vital for an enjoyable day out, which is where a good lightweight trekking backpack comes in. Technical, feather-light and hard-wearing, these thoroughly modern packs allow for 30 to 50-litres or more to be safely stored, without the bulk on your back.
We've rounded up some of the best, many of which incorporate cutting-edge textiles to ensure water-proofing, rip-resistance and maximum comfort, all while keeping an eye on the scales to ensure you're not burning excess calories on the next hike or trip ip a mountain.
All of the packs mentioned on this page are suitable for multi-day trips or wild camping and most will happily transport everything from a few snacks and some additional layers to full-on ropes, poles and more specialist climbing kit.
Although generally pricier than less technical backpacks, the good news is that a good quality lightweight trekking backpack could be the only rucksack you’ll need for a vast range of outdoor pursuits, bigger than a small daysack, but large enough for an overnight camping trip, it's a wise investment without the additional weight to lug around.
The best lightweight trekking backpacks
Arc’teryx Alpha AR55 Rucksack
- Requires clever packing
- Could be too small for serious Alpinists
The Arc'teryx Alpha AR55 is a classic alpine sac with clean lines and minimal faffery to distract, catch on passing foliage or break, which makes it ideal for pretty much any outdoor endeavour.
Weighing in at a mere 1.3kg, it can be stripped down further by removing the framesheet and the top lid, but this removes comfort too, so only advisable for short and light summit days and the like.
The nylon material is beefed up significantly with a liquid crystal polymer ripstop grid that boosts abrasion resistance, and the bungee/daisy chain combination is ideal for strapping gear down without complexity or hassle.
Finally, and arguably most importantly, the hipbelt and shoulder straps are well-padded but surprisingly comfortable in use, keeping weight to a minimum but still giving enough comfort for long days on the trail.
Decathlon Forclaz Easyfit Rucksack 50L
- Easy to use
- It’s huge
- On the heavier side
Sometimes outdoor gear can get very spendy indeed, and this is the kind of item that offers an antidote to all that, coming in at under 50 notes, but still offering many of the features you’d expect in a quality lightweight trekking rucksack.
The automatic back size adjustment adds a little weight and complexity, but does the job, as does the rest of the harness system.
There are plenty of pockets and dividers, as well as a central zip to aid easy access to the small bits that inevitably fall to the bottom of the pack.
At 1.6kgs this is at the heavier end of the lightweight spectrum, but it isn’t as heavy as some of the more over-engineered (and eye-waveringly pricey) packs.
Finally, Decathlon has eschewed dye baths in favour of dope dying (a method that removes a step in the dying process), a move that reduces CO2 emissions by 35 percent in this model alone.
Mountain Hardwear Alpine Light 35L
- Minimalist hip belt
In the outdoors generally, light is usually right, and the Alpine Light 35L backpack from Mountain Hardwear eschews much of the additional bulk that adds weight.
Weighing in at a mere 765g, this is genuinely lightweight, and with a 35 litre volume, there’s plenty of space for all but the biggest kit list.
There’s a trick behind that light weight though, and that’s the construction material - lightweight, durable and waterproof Dyneema has been used, which is 15-times stronger than steel pound for pound.
Three internal pockets (one removable) give storage space for smaller items, such as head torches and snacks, while the main harness is padded for comfort without adding weight or faff.
The only downside is the minimalist hipbelt, which works perfectly well for lighter loads but could lack long-term comfort when carrying lots of kit.
Alas, this is all about cutting weight to a practical-yet-still hardwearing minimum, which it succeeds in beautifully.
Osprey Stratos 34 Rucksack
- Loads of pockets,
- Great ventilated back system
- Can be complicated
- Not super-light
One of the annoyances of carrying a rucksack in warmer climes - or indeed up a hill of any size too - is the dreaded sweaty back that can ruin the best-planned layering system.
Many rucksack makers have tried to beat it, but one of the best systems going is Osprey's AntiGravity and Airspeed suspension system, which in the case of the Stratos 34 rucksack, combines a single-piece back panel and hip belt with breathable suspended mesh to keep as much air moving as possible.
There’s an ingenious toggle system to adjust the back length, as well as enough pockets to store everything you might need. If you need more pockets you’re clearly carrying too much stuff.
In spite of the plethora of pockets and neat touches like the zip pulls, which are all designed for gloved fingers, the Osprey Stratos 34 rucksack only weighs in at 1.4 kgs, and with 34 litres of storage, there’s plenty of space for summer trekking gear.
Berghaus Fast Hike 32L Backpack
- Hilariously light
- Not super-robust
- Not ideal for big loads
The Berghaus Fast Hike 32L Backpack might not be the most robust rucksack in the world, but you’ll be hard-pressed to find lighter, or one with such a solid array of features.
Weighing in at a featherlight 600g boxfresh, it can be stripped down even further to just a shade under half a kilo if you’re really gram-counting.
There’s a decent - if lightweight - hipbelt, with an in-built pocket large enough for a softflask, side bottle pockets and even provision for a hydration sleeve, impressively.
The compression straps allow awkward loads to be securely lashed down, and the side daisy chains will hold walking poles and the like securely.
Finally, the dry-bag-style roll top closure is super-easy to operate in all conditions, and allows the volume of the pack to change very quickly and easily.
Essentially, as a lightweight all-rounder that won’t break the bank, this is an excellent choice for pretty much all outdoor occasions.
What to look for in a lightweight backpack
The key to choosing the right lightweight trekking backpack is to pick one that fits your torso size. This measure varies between brands, and is essentially the distance between your hips (where the hip-belt needs to sit comfortably) and your shoulders. The trick is to have a fit that allows the hipbelt to take the vast majority of the weight, mostly using the shoulder straps for stability.
The next question on the list is size - although for trekking 35-55 litres should be ideal, this does depend on conditions and situation. Summer on the South Downs is a different proposition to winter in Patagonia, and the amount of stuff you’ll want along for the ride will vary just as much. Try and choose the minimum size you can get away with, rather than a much bigger model with extra space "just in case". You’ll inevitably take more stuff than you actually need with a bigger rucksack, leading to a less pleasant experience.
Materials and build quality are a key thing to bear in mind. Most rucksacks are made from lightweight nylon, which can wear very quickly in tougher conditions. Robust alpine-style packs are often the toughest and simplest, sometimes made from cutting-edge materials such as Dyneema or reinforced fabric. These might cost a touch more, but in many cases will last for decades.
Although even the most basic harness systems will serve pretty well, there are a variety of suspension systems on the market, which basically keep the mass of the rucksack from making direct contact with your back. These can be useful for staying cooler in warm climates, but can be overly complicated for four-season conditions or more rugged trips (they’re a pest when filled with spindrift, for example.)
The price is right
Finally, cost can be a big factor in rucksack choice, but a well-chosen lightweight trekking backpack will last for decades. It’s well worth choosing one that fits you perfectly, and will accompany you on years worth of adventures, rather than cheaping out on a short-term 'bargain'.