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2023 Weighted Pack Trials

August 2023
Author: Forest Pike

 As mountain hunting in the West continues to evolve on a spectrum of both methodical and mobile strategy, our selection of the technical gear that accompanies us becomes increasingly more involved. It seems that new proprietary technologies with “catchy” names are being released every year, and advancements in design approach are being achieved just as often. With this in mind and the ever-increasing cost that coincides with technical gear, selecting the right backpack for the majority of your use applications has never been more important. Therefore, we set out to determine which of the top backpacks for 2023 would provide the greatest “comfort under load” experience with refined focus on their frames and suspension.

Appropriately-sized frames and suspension were selected from among the current 4500-6000 cubic inch backpacks from Exo Mtn Gear, Kifaru, KUIU, Mystery Ranch, and Stone Glacier. Each backpack was closely examined in the days prior to the weighted comparison trials, ultimately allowing our team the chance to familiarize themselves with their various techniques for adjustment, differences in bag design, solutions for cargo securement, and ever- popular meat shelves. Thereafter, each team member carried each backpack with both 50 lb. and 100 lb. load configurations over mountainous terrain for about a mile per iteration. Here’s a bird’s eye view of the highlights from each of the five backpacks, specific to their performance with comfort under load.


As Stone Glacier continues to affirm their technical expertise in redefining the capabilities of ultralight, the Sky 5900 bag design remains a constant offering, and for good reason. This system, whether paired with their Xcurve or Krux frame, continues to offer that timeless, minimalist approach to sustained backpacking in remote areas. It’s difficult to think that such an ultralight system could effectively carry 100 lbs. so comfortably, but then again, there’s something to be said about a company with roots that begin with backpack design and development.

Stone Glacier’s Sky 5900 with Krux frame was extraordinarily comfortable under load for the duration of the weighted comparison trials. The overall height and circumference of the waist belt was sufficient for both short and long-term usage, and any on-the- move adjustment held securely without inadvertently loosening on the trail over time. The material selection used within the waist belt, lumbar pad, and shoulder straps provided notable comfort and support. Also, it was very easy to achieve proper contact between all frame and suspension surfaces and the body of each user, despite variances in their physique, which lent the 5 lbs. 1.4 oz. system to carry 100 lbs. incredibly well for each team member.


With the arrival and unboxing of the new K4 5000 from Exo Mtn Gear, to say there was incredible anticipation would be an understatement. Our team’s prior experiences with earlier systems of the brand had all been favorable. Their unrelenting focus was readily apparent with the latest release of their K4 system, and the fact that they spent the previous 3+ years designing it didn’t fall on deaf ears. With the new K4 5000 in hand, the team knew Exo Mtn Gear had achieved something special.

What’s the bottom line up front? The K4 5000 is uniquely intuitive and effective when it comes to comfort under heavy load. It quickly rivaled the noteworthy performance of Stone Glacier with concern to sustained comfort and even excelled further in the area of achievable posture. With noticeably shorter frame stays, the K4 5000 permitted each user to stand more upright in comparison to other packs, which contributed to more enjoyable pauses on the trail. Another standout element of this backpack’s design was the angled side straps that held the load on an upward vector toward the frame and effectively reduced any lateral load-shifting across the shoulders of each user. Ultimately, the K4 5000 provided both sustained comfort and good posture for each user while carrying 50 and 100 lb. loads, and we’re happy to report that the newest system from Exo Mtn Gear is solid in every capacity.


The latest backpack released by Kifaru, the Bedlam, arrived on their tried-and-true Duplex Lite Frame. After our team’s initial review of the complete system, it was readily apparent that Kifaru takes their “Gear for Life” pitch very seriously. Although significantly heavier and with lesser carrying capacity than other backpacks used in the weighted comparison trials (6 lbs. 8 oz. and 4900 cubic inches to be exact), the Bedlam screamed load-bearing capability and durability.

With the tallest and thinnest waist belt of the group, the Bedlam was able to effectively posture the majority yield of the heavy loads to each user’s hips where it belongs. The focal point of that load transfer was brought to the hips by means of the aggressive lumbar pad, which proved itself very trail worthy under such heavy loads. Padding found in the shoulder straps was notably stiffer than that found in some of the other backpacks, but the successive strapping along the frame held the shoulder straps very securely and in an upright fashion along the user’s back curvature. In the end, the Kifaru Bedlam was made for carrying heavy loads over sustained distance in mountainous terrain and with a military-like approach. This offering from Kifaru may not whisper encouraging comments of affirmation in your ear when the going gets tough out there, but that’s not how the United States military became back-to-back World War Champions either.


KUIU’s Pro 6000 came in at 6 lbs. 2 oz. and hosted a variety of proprietary-like hardware, webbing techniques, and material selections. Many of the strap and webbing configurations were of a slimmer profile (i.e. 3/4" width vs. 1" width), likely due to the nature of this system being a flagship product offered by a refined, ultralight brand such as KUIU. The Pro 6000 frame and suspension system offered significant adjustability and a carbon fiber frame that tapered narrower near the lumbar pad. If anything was easily discernible during our initial familiarization with the system, it was the fact that it had more uniqueness and proprietary design elements than other backpacks of the group.

With the most perforated fabric design of the group concerning the surfaces of the frame and suspension that contact the user, the comfort under load provided by the KUIU Pro 6000 varied over distance and terrain by user. The rubber-like coating found some surfaces sometimes caused more distraction than comfort, often pulling at some users’ clothing awkwardly. Additionally, there were times of significant lateral shifting of the load while traversing uneven terrain, which lent itself to inducing increased acute and cumulative fatigue. It is believed that KUIU’s Pack Load Hauler would have greatly reduced this lateral load shifting, but unfortunately, we didn’t have it on hand for the weighted trial comparisons nor did we include any accessories from any brand in our efforts. Ultimately, the KUIU Pro 6000 was able to get the job done when it came to carrying heavy loads but with mixed results from our team.


Mounted on Mystery Ranch’s Guide Lite MT Frame, the Beartooth 80 came with a five- piece waist belt and yoke-like shoulder strap design. The frame itself was likely the most unique of the backpacks found in the group. It was very flexible yet sturdy. If you’ve ever seen a multi-day hunting backpack from the Mystery Ranch lineup in recent years, then we’re confident you know what we’re saying here. Additionally, and much like the KUIU Pro 6000, the Beartooth 80 hosted a variety of proprietary-like design features that were perhaps more detailed and complex than is truly necessary. These type design and manufacturing differences are common amongst products manufactured in the United States and those from Southeast Asia, as the Mystery Ranch Beartooth 80 is from the latter.

When carrying heavy loads over mountainous terrain, we found the five- piece waist belt design effectively limited its ability to contour with the user’s waist. Each hinge found between waist belt segments produced a gap between it and the user, which didn’t appear to be ideal when attempting to transfer the majority yield of a 100-pound load to the hips. Additionally, the fixed yoke-like shoulder strap design limited the adjustability of the frame system to the user and at times forced their shoulders awkwardly (and uncomfortably) outward. Ultimately, there were periods along each iteration that were more comfortable than others with the Mystery Ranch Beartooth 80.

When considering the more forgiving cost of this system compared to others in the group, it’s likely that this system will both appeal and get the job done for those who hunt the backcountry on a lesser frequency.
What’s our conclusion, you may ask? Well, the truth is the proper selection of a backpack for hunting out west boils down to the individual user themself. Their preferences with bag design and selection may outweigh the importance of a system’s ability to provide comfort under load with such bag-specifics orienting around built-in organizational features, ease of accessibility, and modularity. Also, proper backpack selection relies heavily on the individual’s ability to adjust and fit it properly to themself. Although we found both the Stone Glacier Sky 5900 and
Exo Mtn Gear K4 5000 to provide the greatest comfort under load for ourselves, it doesn’t mean that these systems would provide the same for an individual who doesn’t understand how to adjust and fit it properly. In fact, their system experiences could prove vastly different. With concern to the products vetted here from Stone Glacier and Exo Mtn Gear, although they both carry heavy weight comfortably, they each have a very different bag design when it comes to storage and accessibility.

Basically, do your research and exhaust all of your technical resources (such as Gear Fool) to ensure the optimized enhancement of future backcountry experiences. Have a gear-related question we may help you with? Contact us at and our team would be happy to help!