The Flex Hike 20-30L by Sierra Designs is an ultra-light day pack that is built to expand and contract to shift between a 20 and 30 liter volume on the fly. This is my review.
The Flex Hike 20-30 is a relatively simple backpack in terms of features. It has a large main compartment that adjusts between 20 and 30 liters in capacity by means of pulling three compressions straps that run horizontally along and through the fabric of the pack. It has a single, double zippered top lid compartment that is accessible from above and houses a hidden stash pocket, two mesh water bottle pockets, and a side access compartment. It features height-adjustable shoulder straps, thick padded hip belts with small but stretchy storage nooks, and a breathable yet padded back panel. It weighs 1 lb. 14 oz. and retails for $149.95.
What I liked
The highly compressible design aspects of this pack are actually quite great. Unlike most packs that have a couple of simple cinches that help stabilize the pack when they’re hauling smaller loads, the Flex Hike actually runs the strap through, round and outside the pack. This allows it to close in from almost every angle, from the top all the way to the bottom of the pack. Stuffed full or half empty, the pack can really squeeze down and keep everything in place, which results in more stability and efficiency on the trail. The process of adjusting it down is relatively easy too. Just pull on the strap to bring it in, or lift on the tab to let it back out. I use this feature every time I pack my bag and greatly appreciate the fastness it brings. I especially like that on longer hikes as my soft water bottles and food supplies are depleted, the pack doesn’t get loose and flappy from the lack of fill. As a bonus, my gear doesn’t rattle around inside, which keeps things quiet on the trail too.
Comfort for the most part is very good but does come with a catch which I’ll get back to later. The shoulders, back and hip pads I can only describe as cushy and airy, which is not a way that I’ve ever had to describe a backpack before. The cushions are thick, highly compressible and have this low density feel to them that reminds me of a sponge, but in a good way. They wrap around the body and distribute weight extremely well. The hip pads in particular feel like a gentle hug from a tree sloth (I assume) and stay comfortable no matter how much I shift, move, or weigh them down with gear. Basically, the pads feel great despite being so lightweight and breathable.
Organization is good, with enough compartments to keep gear, food, water and emergency equipment all separate but easy to access. The hidden side pocket is great for keys and a phone, while the top pocket is perfect for things like headlamps, gloves and other items you may want quick access to. The hip belts have small pockets that can hold granola or small snacks, and the mesh pockets on the sides easily hold large water bottles, or smaller bottles without them slipping out. Trekking poles can slip under the compression straps without issue and everything else can basically be dumped into the main compartment.
Build quality is very good despite the light weight. The pack is mostly built out of 100 denier nylon honeycomb (for ripstop like tear resistance) and much higher denier 420 denier oxford in high stress areas like the bottom of the pack and the shoulder and hip straps. The combination works great to prevent scuffs and tears where they are likely to happen, with lighter materials shedding weight where it makes sense. The materials themselves are great quality and feel premium to the touch, in spite of the light weight. Stitching and fabric consistency are both great, with no issues being found on my sample.
Pack weight is of course great at under 1 pound 14 ounces and makes a lot of sense for a pack that is meant to be both a low pack weight, short hike bag and a higher volume, full day epics hauler.
What I didn’t like
The adjustable height shoulder straps aren’t a very successful design in my opinion. While they are easy to adjust and they do in fact allow the pack to fit a wider variety of body heights, the issue comes down to how they do it. Ideally, one wants the fantastic hip belt to land on, well, the hips, and the pack to sits close against the back. However, to do so most users will have to let a good deal of slack out of the shoulders to do so. The result is a pack that hangs very far down on the back for even moderate height hikers, which makes it feel floppy, sloppy and generally just not stable as it no longer sits against the back properly along the shoulders. The better option for light loads is to just keep the shoulder straps pulled tight and let the hip pads land wherever they do, which for me is across or even above my belly button, and I’m only 5’8″. This is actually quite comfortable, but does greatly eliminate the benefit of having thick, luscious hip pads, which is transferring the weight of the pack to the hips. At higher pack weights this is a bummer as it can put the weight of the pack on the neck and shoulders, so its probably better to let out the shoulders at that point and deal with the floppy sensation, just to avoid the neck tension. This won’t be an issue with short torso users, but moderate and especially taller hikers are likely to notice. Now, in their defense, adjustable length isn’t a common feature at this price range, so at least they managed to squeeze it in on such an affordable pack.
Digging all the way to the bottom of the pack in the main compartment can be a slight nuisance. There is no side or bottom access, and if the pack is cinched down tight you have to undo the straps a bit to get down there. It’s not horrible, but something to keep in mind. Otherwise things are very convenient to get to.
Notes for best fit
As I found myself struggling with this at first, this is how I found to get the best fit and most comfortable usage out of this pack. Loosen up all the straps, pull the adjustable shoulder/load straps tight. Clip the chest, adjust that down, then adjust the under arm straps to your preference. Finally, deal with the hip straps last. Only adjust the shoulder straps if necessary.
Overall
The Flex Hike is a good bag with some neat features. I found myself using the adjustable volume every single time I packed my bag. I enjoyed cinching it down on the trail once my pack lightened up from having less food, water and layers inside to prevent the pack from becoming loose and wobbly. It is rather comfortable despite a limited height adjustment system thanks largely due to the cushy hip and shoulders straps. It is light enough that it never weighed me down on the trail, but still managed to handle 25 pound pack weights rather well. Breathability is good, durability is great, and the price isn’t bad either.
Recommended
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