Welcome! Ultralight backpacking is my passion, and keeping up on new technologies, gear, and techniques relevant to UL backpacking is what floats my boat. I'm always looking for the lightest, most functional gear to improve a lightweight or ultralight backpacking kit, and report my impressions and field testing results here. For hikers wanting to keep up on the latest and greatest ultralight backpacking gear, this is a good place to hang out. Also, there is a lot of information here (and on our informational website Southwest Ultralight Backpacking) on useful techniques and backcountry etiquette -- food for thought for hikers wanting to lighten their load and their impacts.

My goal for Ultralight Insights is to understand, test, and report on new technologies and gear of interest to lightweight and ultralight backpackers. It's a passion after all, so we just plain enjoy talking about it. I hope readers will add their own wisdom and comments, respond to my questions, ask their own questions, and correct me if I get something wrong. Happy hiking! Will

Tuesday, March 26, 2013

GEAR REVIEW: Elemental Horizons Aduro SL Backpack

By Will Rietveld

The Aduro SL is next in a series of backpacks from a new small company called Elemental Horizons. I reviewed the 59 Liter Aquilo (ideally sized for lightweight backpacking), for Backpacking Light Magazine, and gave it a rare Highly Recommended rating. Next in line was the 48 Liter Kalais (for the lower end of lightweight backpacking, or ultralight backpacking for long intervals between resupplies), which I reviewed on this site. And now I have the privilege to review the 42 Liter Aduro SL, suitable for ultralight backpacking and as a multi-purpose day pack.

Unlike the top-loading Aquilo and Kalais, the new Aduro SL is a front loader, meaning it has a zipper across the top for access. The volume of the Aduro SL is 2556 cubic inches (42 liters), and it costs $215.

 Specifications and Features

Manufacturer and Model
S/M, M/L
2556 cu in (42 L)
Size M/L tested. Without Air Frame mfr wt 20.5 oz, measured wt 20.45; with Air Frame mfr wt 23.7 oz, measured wt 24.25
70 denier urethane-coated ripstop nylon (blue), 210d Dyneema-X (black) in high wear areas, 30 denier silnylon on the inner panels and front pocket baffles, and spacer mesh in the backpanel, shoulder straps, and hipbelt
Panel-loading via top water-resistant zipper, large front pocket with water-resistant zipper, front cord lattice, 2 compression straps each side, 2 Dyneema X side pockets, interior framesheet pocket, load lifters, padded hipbelt with stabilizers, sternum strap, haul loop, ice axe loop
Air Beam ($45, 3.8 oz), hipbelt pockets ($15/$18, 0.9/1.4 oz), hydration sleeve ($24, 1.2 oz)

The photos below provide several views of the Aduro fully packed.

Suspension – A unique feature of the Aduro is a full height pocket on the inside of the backpanel to accommodate a Klymit Air Beam Framesheet (sold separately), or other framesheet. The Air Beam is pumped up with the provided bulb to make it very firm and vertically rigid, so it acts as a frame for the pack.
Fontpanel View – The Aduro SL has a large front pocket with a full height water-resistant zipper on the side. Overlaid on the front pocket is a rigid cord lattice for attaching items to the front of the pack. 

Backpanel View – The backpanel is padded with spacer mesh, as is the inside of the 2.25- inch wide shoulder straps and 4-inch wide non-removable hipbelt. The hipbelt is a center pull design that operates very smoothly and really snugs the pack to your hips.

Side View – Each side of the pack has two compression straps, with the lower one having a Y-shape. The depth of the front pocket is shown in this photo. Also each side has a large side pocket made of durable Dyneema-X fabric. Each is large enough to hold much more than a water bottle. A water bottle needs to be tucked in as shown to keep it from falling out.

Top View – A water-resistant Uretek zipper, with two sliders, curves over the top of the pack and half way down each side. The upper compression straps must be released to fully open the zipper.
Field Testing and Assessment
I tested the Aduro with loads ranging from 10 to 30 pounds while snowshoeing, backcountry skiing, day hiking, and a multi-day ski trip to a backcountry cabin, for a total of 31 days of use.

Carrying the Aduro on an all-day snowshoeing trip.

Overall, I found the Aduro to be very versatile, performing equally well as a snow sports pack, day hiking pack, and multi-day backpack. On one trip I carried my backcountry skis on the sides of the loaded pack A-frame style with the tips tied together, while I climbed on snowshoes 800 feet up to a favorite skiing area. I slid the skis under the compression straps on each side; the system worked perfectly.

I racked up a lot of miles on the pack by doing a morning day hike up a nearby mountain, where I climbed 1500 feet in 2.5 miles to the top then jogged back. Each day I tested a different frame option and pack weight, from 15 to 30 pounds. The frame options I tested were: none, the Klymit Air Beam inflated to different levels, a corrugated plastic framesheet, a single layer of stiff closed cell foam, and a folded closed cell foam pad – each one tightly confined in the backpanel sleeve.

My primary finding is the Aduro carries much better with a frame of some kind confined in the backpanel sleeve, than it does without a frame. I carried a 30 pound load without a frame and found the weight uncomfortably concentrated on my lower back. With a frame, the pack effectively transferred weight to my hips, with very little weight carried on my shoulders. I typically located the hipbelt on top of my hips and tightened the hipbelt very tight so it would not slide down. Doing that, the pack carried comfortably and I was able to release the sternum strap, which is a good indicator that a pack is transferring weight.

Close-up view of the hipbelt and lumbar area. The wide wrap-around hipbelt combined with the center pull hipbelt tightening system are key design elements that allow the Aduro SL to comfortably carry a load.

Although the Air Beam framesheet performed well, it did not perform any better than the other framesheet options listed above. The closed cell foam pad was a folded Gossamer Gear Nightlight pad, and the corrugated plastic framesheet was bent in an S-shape to fit the contours of my backside. The rigid closed cell foam was some I had laying around and is similar to the framesheet in the GoLite Jam pack.

One thing I noticed about the Air Beam is it slowly loses pressure, so it needs to be pumped hard again every few days. I did not notice any effect of Air Beam air pressure on how the pack carried; as long as it was pumped fairly firm and the pack was fully extended, it felt the same.

Overall, the Air Beam is an innovative departure from a conventional contoured tubular aluminum frame (like those in the Aquilo and Kalais), but it is not necessarily any better.  My personal preference (call me old fashioned) is for the contoured aluminum frame because it can be shaped to exactly fit the contour of my backside, and it holds that shape no matter how full the pack is. And it doesn’t need to be re-inflated.

Making a framesheet from corrugated plastic is easy and cheap. Corrugated plastic is available from office supply stores, and a 24-inch long x about 10-inch wide piece fits the pocket perfectly. Simply cut it to size, have someone put it against your back and kink it at the top of your shoulders and near the bottom, and slide it into the sleeve. A stiff closed cell foam framesheet works even better; I cut a piece from an old sleeping pad. Its important that the framesheet use fits tightly, vertically and horizontally, in the pack’s backpanel sleeve.

Accessing the interior of the panel-loading Aduro SL is about the same effort as a conventional top-loading pack: open the zipper and reach in if your item is near the top, or if your item is near the bottom, release the top compression straps and unzip it entry entirely. For loading, it helps to lay the pack on the ground with the front pocket facing up and load it while closing the zipper from each side.

Not everyone likes a panel-loader, but it’s that feature that makes the Aduro so versatile. It has enough volume to carry a typical ultralight backpacking gear kit plus food, water, and fuel for up to six days. The same pack is ideal for snow sports because it’s quite durable and snow-proof on the outside. Ditto for day hiking and it will shed a shower quite well without a pack cover (but water will eventually leak through the seams).

How lightweight is the Aduro? Well, at 20.5 ounces without the Air Beam, it is about 5 ounces heavier than the Gossamer Gear Kumo pack, and has 350 cubic inches more volume. The Kumo has only a 1-inch wide waist strap, while the Aduro has a 4-inch wide wrap-around hipbelt. Consider that extra 5 ounces to be all comfort.

Overall, the Aduro is sized for ultralight backpacking, but it’s not the lightest pack available for that purpose. Elemental Horizons designs packs for comfort and load carrying capacity first, and for light weight second. If you place your priorities on comfort, load carrying capacity, durability, and lightweight in that order, then the Aduro is your pack. It’s lightweight and capable, and very well made.


  1. Will, any follow-up experience with the Aduro? I'm seriously considering it (love my Aquilo but it's usually too big). Also, you note that it worked well with a folded Nightlight (18"-19" x 11" x 2.25" per GG) or with 24" x 10" corrugated plastic in place of the Airbeam. Does this mean that you didn't have any issues with the Nightlight being a few inches shorter than the pocket? Also, how difficult was it to remove/replace the Nightlight? I like the idea of using the frame as sleeping pad (currently using a torso-length Z-lite in warm weather).

    Will W