Buyers' Guide - Big Packs

One aspect of pack purchase that's sometimes overlooked is the actual buying process. It's crucial though and worth taking some time over to get a comfortable fit - remember, everyone varies and what works well for someone else, may not be as effective for you.

If you can, go shopping at a quiet time when shop staff aren't rushed off their feet. Get them to load up the pack with a heavyish load - some good shops have special bags for this, or climbing ropes are a good substitute - and ask them to help you adjust the sac precisely to fit you.

Walk around for a bit and see just how it really feels. Does the load feel stable if you swing around? Is the weight transferred effectively onto your hips or does it feel high up and unbalanced? Are the straps and hip-belt comfortable or do they cut in and hurt?

Bear in mind that the foam used in pack padding will bed in slightly with use, but if the fit is wrong to start with, look elsewhere. It's worth getting it right as an uncomfortable pack will ruin your trip, full stop :-(

At first glance, there seems to be a huge number of different back systems out there, but the majority work in roughly the same way. An internal frame, often two metal stays, feeds the load into the hip-belt area while some sort of foam padding cushions the back and allegedly provides ventilation and wicking capabilities. Simple really...

Adjustable back systems allow the manufacturers to make one size of pack to suit a number of back lengths, which is great if you intend to share the pack with a number of friends of disparate proportions, but for most people, it's a question of adjusting the pack once to fit their back length, then leaving it alone. For that reason, ease of adjustment doesn't really count. More important is security and robustness once adjusted.

Fixed back length systems mean that the manufacturer has to produce packs in different back lengths so you must choose the right length for optimum performance. They're simpler, potentially lighter and can be more robust.

All the bells and whistles in the world mean nothing if the pack doesn't feel right, so don't be intimidated by fancy systems and whacky technology...

The hip-belt is one of the most crucial parts of the pack. When it works properly, it should help to transfer weight through to the hips and keep the pack stable and comfortable. In our experience, the belts that work best have a hardish outer shell for support with a softer inner layer than conforms to the hips for comfort and support.

The best belts like those made by Osprey and Berghaus's Bioflex, are also cupped and relieved to take account of the hip bones and optimise fit. Osprey now even offer a mouldable hip-belt on their top-end packs which simulated the effect of around six months of use for a better personal fit.

Many of the best packs we've used channel the staves of the back system directly into the hip-belt for the most direct possible load transfer, so pay particular attention to how the hip-belt is attached to the rest of the sac. If it's just sort of hanging there, you may not get effective load transfer and could also suffer from poor stability.

Shoulder straps seem to work best when they're contoured ergonomically - think S-shaped - and use a dense to medium dense foam in a medim to narrow strap. You may thing soft, wide straps are the way to go, but in practice, they don't offer enough support.

Look too for top-tensioning straps at the very top of the shoulder straps which allow you to pull the top of the pack in towards your head for increased stability.

If you're a woman, take the time to seek out a women's specific design. Women generally have narrower shoulders, shorter back lengths and wider, more pronounced hips and a well-designed women's pack will take account of all these to produce a pack that's more likely to fit you better.

If a man's pack fits you better, then that's fine, we're all different shapes, but many women will find a women's specific design works better for them. If you're a small bloke, it may be that a women's pack fits you too, so don't get sniffy about it...

You'll find that most large capacity packs have a main compartment - think a bloody big bag - and possibly a lower 'sleeping bag' section, that may have a removable divider. You don't have to use it for a sleeping bag by the way, it may make more sense to carry a dense, heavy object like a tent there to keep weight low and improve stability.

It's all down to personal preference but compartments make it easier to organiser your load rather than just chucking it all in. We llke a large lid pocket for easy access to frequently used stuff like snacks, hats, gloves and so on.

Side pockets, many fold flat, are similarly handy, but bear in mind that for any sort of mountaineering, a wider pack may get in the way and scrape on rock. For general backpacking though, they're great.

Many packs now have built-in hydration system pockets and outlets - they're fine at the start of the day, but re-filling may require an annoying re-pack of the sac. It may be better to sit the bladder at the top of the pack, in a side pocket or even use water bottles.

Let's face it, most of us trust the big brands to get it basically right and use proven construction methods and decent fabrics. Look for triple-sewn seams where the fabric of the pack body is sewn together with an overlay of protective tape reinforcing the seam and protecting it from abrasion.

You can tell a bit from the feel of fabrics as well - if it's light and soft feeling, it's probably not going to be as durable as tougher feeling fabric. Finally, look for a reinforced base, either a double fabric layer or a heavier, more durable material as this area takes a real kicking over the years.

On the back system, soft wicking mesh fabrics may work well when new, but bear in mind that they'll wear with use particularly if they pass over the edges of foam pads, look for reinforcement in those areas if durability matters. The same is true of straps.

Waterproofing most packs use water resistant material, but will leak through the seams. Macpac has a good reputation for conventional water resistance, however both Berghaus and Force Ten now use welding and taping techniques to produce water proof packs at a price.

Most users will need either a pack cover or a waterproof liner or liners to protect their kit in wet conditions.

If you really, really want to save weight then you can opt for a minimalist pack, possibly from the likes of GoLite or Gregory, but there are others out there. Really ultralightweight backpacking is a topic all of its own, but the key to understanding it, particularly if you want a pack like GoLite's Gust. which has no back suspension system at all, is that there are no half measures.

If you opt for a pack with no support then you'll also need the lightest sleeping bag, shelter and clothing you can find plus the nouse to pack them so they don't dig into your back. You also need to bear in mind that while light is great, it's also demanding. Remember too that while lightweight fabrics and materials are proportionately tougher than ever before, they're also less durable than full-weight materials.

We're not saying that you shouldn't aim to lose weight, but bear in mind that well-engineered back systems aren't always the lightest option even if they do offer the best -carrying experience with a heavy load.

If you carry trekking poles or ice tools then make sure you have the relevant attachments, ditto skis, which require reinforced side pockets and straps. If you're going to be climbing, consider a technical sac with gear loops sewn onto the hip-belt.

Arguably the biggest gizmo of all is the Berghaus Bioflex system, which offers incredible mobility allowing you much more freedom of movement. We're not going to go info detail here, but it's a brilliant carry particularly on uneven ground where you may need to take high steps and wobble around. The downside is that if the back system were to break in the field, it would be far harder to repair than a more conventional pack system.

More Help and Advice

This article should have given you some basic pointers. The good news is that there's a load more advice on OUTDOORSmagic:

• Ask on the gear forum about general issues or specific items.
  
• Check the member reviews section for user experiences of kit.
  
• See OM editorial reviews on the front of the site for our impressions.
  
• Ask Richard Gear if you have a specific question you need answering.