For the last couple of seasons I have mainly been reviewing luxury, high-comfort trekking bags. Even though the Hyperlite Mountain Gear Southwest 3400 is a tried-and-true thru-hiker's backpack, I thought it was high time that I shared my full breakdown of it.
A recent, multi-day excursion into Wyoming's Wind River Range was my first real-world experience with this pack. And for many people new to backpacking, or new to the BackpackingTV community, this may be their first time hearing about this ultralight option. So let's get into what separates this bag from the herd, what I loved, what the trade-offs were, and why you might want to check this guy out for your own adventures.
ABOUT THE HYPERLITE 3400 PACK
Price: $379.00 (USD)
Weight: 2.18 lbs/34.9 oz/989g (Black) and 1.98 lbs/31.7 oz/899g (White)
Internal Volume: 3,400 cu in./55L
Strap Padding: 1/8th-inch foam
How many liters is the Hyperlite 3400?
The “3400” part of the name, Hyperlite Mountain Gear Southwest 3400, refers to the interior capacity of the backpack in cubic inches. This capacity measurement is a departure from the market's typical liter-based scale. So to help you compare across brands, 3,400 cubic inches works out to roughly 55 liters.
How do you pack the Hyperlite 3400?
The Hyperlite Mountain Gear Southwest 3400 Backpack is essentially a big tube. Since it doesn’t have compartments, or a front access point, the only way to pack it is just by stuffing things in (remember to put the heavier stuff on the bottom).
Use packing cubes
I'd recommend using packing cubes to help give you a bit of organization (plus, they help make efficient use of the space). But even though there aren't built-in compartments, this backpack does have a generous overflow pocket (which is also made of Dyneema fabric). This pouch gives you an extra 600 cubic inches of packing capacity, which I loved using for all the things that I wanted easy access to (i.e. water bottles, trekking poles, rain jacket, head lamp, map, etc.).
Hip belt
Finally, there is also the Dyneema fabric hip belt, which has a pocket on each side, sealed with waterproof zippers. This is definitely the go-to spot for a cell phone, wallet, or anything else that you don't want to get wet.
Rolls down to tailor the fit
A cool design feature of this pack is that it can roll down and tailor its fit to smaller amounts of gear. When in this configuration, some straps that come over top of the bag can act as an overload point for storing extra, bulky (but hopefully light) items. Or, those same straps can just be used to cinch down the pack even tighter. So whether you’re hauling a full, multi-day load, or simply rocking a day-trip, the HMG Southwest 3400 is up to the task.
Is the Hyperlite Southwest waterproof?
The Dyneema material that Hyperlite Mountain Gear uses is 100% waterproof (and hugely durable). However, sewing Dyneema into a backpack makes it slightly vulnerable to saturation.
HMG does a great job of taping and sealing those attachment points, which again helps make the Southwest 3400 essentially waterproof. So as long as the user seals the top flap properly, hiking with Hyperlite's backpacks is as close to waterproof as you can get without hauling a full-on dry bag.
Is Hyperlite comfortable?
Comfort is the Southwest 3400's biggest weakness. In order for it to save weight (the pack weighs only 2.18 lbs/34.9 oz/989g), those plush shoulder/hip straps had to be stripped away. To be more precise, the shoulder straps have 1/8th-inch-thick foam padding, which is below the bare-minimum for comfort, in my opinion.
Field testing the Hyperlite backpack
For my Wind River trip, I was required to carry a bear bin, and I had my camera equipment. I realize that I was pushing the max capacity of this pack. However, by the end, my shoulders were sore in a way that I haven't felt in all my years of backpacking. The trick is don't over pack it. I would say the 3400 Southwest would only be comfortable with 30-pounds or less inside. Anything more, and those thin straps will make their presence known!
Back airflow
Another thing related to comfort (or rather, discomfort) is the absence of airflow with this backpack. Because of the lack of structural features (which I'll get to next), my back was pressed right against the bag the whole time. So even though I was hiking in chillier temperatures, I still built up a good amount of back sweat.
Do Hyperlite packs have frames?
All supportive structures were also stripped away in an effort to cut down the weight of the HMG Southwest 3400. As I've said before, this backpack is like one big tube.
There is no back support or yoke system to tailor the fit. The only adjustments that can be made are the lengths of the shoulder straps, but not the length of the torso or any finer adjustments. This is one of the big trade-offs between an ultralight pack and a heavier, but fancier, classic trekking bag.
Is the Hyperlite pack worth it?
At $379.00 (USD), I would consider the Hyperlite Mountain Gear Southwest 3400 to be in the “high-end” tier of backpacks. So why does such a lightweight, simplistic pack cost so much? Well, there's more than meets the eye. As we've discussed, this pack is made, almost top-to-bottom, with that durable, waterproof Dyneema material.
Fabric of the Hyperlite backpack
The upper portion of the bag is made from 50 denier Dyneema fabric, while the bottom portion is made with a robust 150 denier fabric. This makes the backpack highly resistant to scrapes and tears. I know plenty of veteran hikers who have used Hyperlite packs for years and years, and they are still going strong. So in that sense, it's a high-value backpack if viewed as a long-term investment.
Recommended for Beginner Backpackers
In the end, I wouldn't recommend this as a beginner backpack. I think new hikers would fare a lot better with a comfier, albeit slightly heavier, approach. But if you know what you're doing, are planning some treks through rough terrain, need something that's highly water-resistant, and on top of everything, want the lightest possible load (no matter the cost), then the Southwest 3400 will be well-worth it for you.
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I hope that helps you make sense of this popular, yet polarizing ultralight backpack. I can see both sides of the debate, but I can also easily hone in on what made the 3400 a bomber bag. For more reviews, tips, and epic hiking adventures, check out BackpackingTV or subscribe to the In4Adventure Newsletter.
