Backsystems, sternum straps, packing volume. What does it all mean? If you don’t know exactly what it is you’re looking for, where do you start when trying to choose your next adventure backpack?

While much of this comes down to personal preference and the exact requirements of the adventure or expedition itself, here we breakdown some of the key requirements of any expedition backpack and some of the major differences and specifics you’ll need to think about when choosing your next backpack.

First things first you’ll need to consider its intended use specific to the expedition. Trekking, paddling, mountaineering, whatever your chosen activity, without exception, you’ll need a well thought out luggage solution but those needs are of course likely to differ. So the requirements of the trip ahead will likely help advise much of the decision making and is therefore a great place to start when thinking about buying a new pack.

Pack Volume

In basic terms, depending on your pack load, expedition backpacks can be split into three types. Day packs, backpacking packs and expedition packs. Depending on your plans and your expedition objectives, you might need a combination. On basecamp style expeditions for example, you might hike in which all your kit and then embark on smaller day trips having your main big pack and something significantly smaller will be particularly useful.

Understanding your volume requirements will categorise the types of packs you might be looking at which will provide you with a suitable sized pack. From there you can then decide on the features you do or don’t need.

Day Packs: 6-25l

While there’s a fair bit of variation between how different brands categorise their daypacks we’re basically talking about a compact pack to carry your essentials. Depending on the adventure you have in mind, it might be literally a layer or two and some snacks and water, you might want this to stretch to cover an overnight stay or two but either way what you put in one of these is going to be pretty stripped back.

For backapcks in this range, while you’ll want a proper fitting pack with good functional straps, you won’t require so many fitting features as you might on a larger pack. That’s simply because by carrying less weight the impact on your body is less severe.

A day pack like this is likely to be part of your kit setup on Secret Compass expeditions like Mongolia or Sudan, where the team is vehicle or pack animal supported.

Lightweight backpacking: 30 – 50L

Then for relatively short duration lightweight backpacking trips, we’re talking about the next step up. These are probably the most versatile of packs. The smaller end of the scale won’t be too big for day trips. In summer conditions you’ll get away with a few nights out on one of these, it might force you to make some difficult decisions as to exactly what you do or don’t need but that’s usually a good thing and you’ll be glad of the saved weight and extra manoeuvrability.

For Secret Compass expeditions such as Iraqi Kurdistan and Afghanistan, backpacks in this range will be an ideal component of your luggage setup.

Backpacking: 50 – 70L

An extended backpacking trip or several days of being self-supported with the possibility of  adverse weather and this is your volume category. You’ll be able to pretty much fit everything you’ll need in a pack like this but for the longest self-supported missions. These will come with added adjustability, comfort and support to make sure you’re able to carry a pack like this loaded.

This is the size range you’d be looking to choose from for our Darien Gap or Madagascar expeditions.

Expedition Backpacks 75l+

These are for the big self-supported missions. Expeditions where you’ll be particularly remote and so chances for resupply are slim, where you’ll likely be camping and carrying your entire sleeping system and where the weather conditions are so variable you’ll need all the options.

For these, fit is super critical. And you’ll want every adjustment available to make sure that when fully loaded, these packs aren’t going to cause injury or discomfort.

Some expeditions might require expedition packs in this volume range where you might be required to carry as much as 25kg on back to back days. Needless to say a proper fit is vital on adventures like this.


Of course alongside the straps, the back is the main point of contact between you and the pack. On modern packs it’s also where you’ll find some of the biggest design variations so it’s a point you’ll want to give some consideration. That said, all brands have their own names and trademarks for different systems which means there is a lot to get bogged down in. So with that in mind it’s worth just having a couple of requirements in mind and go from there.

The main thing to consider is of course support. If it’s a big pack, comfort, balance and support should definitely be at the top of the agenda as any niggles or discomfort are likely to be exaggerated with any weight inside. A good, well padded and comfortable hip belt and well built and balanced support in all the main contact points is key.

Similarly, for a day back with much less weight where you’re likely to be moving at greater speed, you might want to prioritise airflow between you and the pack. It all comes down to intended use and environment so it’s important to keep that at the forefront of the decision making.

Size & Fit

There’s no real hard and fast rules on this nor is there a standard way of measuring. But each manufacturer will have a ton of information about how to get the right size pack for you with their own techniques of how to measure and size yourself up against their range.

In whichever size pack you are choosing to buy, it’s important to test the physical pack out on your back, filled with a realistic weight you’re likely to carry on expedition. Only then will you get a real idea of how it fits your back, how easy it is to balance the load properly and what support the pack offers. Each pack should have a high level of adjustability to cover a range of different sizes and body types but ultimately, packs will fit everyone slightly differently and it’s not something you can really fully understand just by reading marketing material so take your time on this to make sure you get it right. Fill up the pack, walk it around the store, adjust it as much as you need to understand how the fitting systems work.

Other Features to Consider

You’ve probably now got a pretty good idea of the kind of pack you’ll be looking at. For most major brands they’ll offer just a couple of packs in each volume category so now it’s possible to consider the finer details and features to decide which is right for you.

Are you going to be using trekking poles or ice axes? Perhaps it’s worth opting for a pack with easy stow-away options for easy access on the move. Do you prefer to use a drinking hose and bladder rather than using a bottle? You might want to think about a pack divider to help you compartmentalise your kit, for example keeping your sleeping system in its own separate compartment.

Again, keep activity and intended environment in mind. Is your pack waterproof or does it come with a waterproof shell to cover it? Might you find a quick access stuff pocket useful if the weather is changeable and you find yourself changing layers frequently?

All Secret Compass expedition handbooks come with a detailed kit list including backpack size suggestions which are a great starting point. If you’re booked onto a Secret Compass expedition and aren’t too sure what you need or want to discuss the options, don’t hesitate to get in touch. We love to chat kit!