Earlier this month I took my first prototype bamboo backpack into the mountains. It served as my primary gear carry for a climb up Mount Langley in the eastern Sierra Nevada. The trip represented more than a first full field test for the pack. It was also the pack's maiden voyage, given that it was expected to perform all functions without any backup alternative in the event of failure. The pack managed wonderfully, and having this chance to use it in the field of course created a lot of real-world experience and information that can now be brought back into the design process.
I forage, salvage, and reclaim bamboo from private property in my neighborhood not far from downtown Los Angeles. It's one way I can locally source perfectly good natural materials for building tipis, geodesic domes, and other kinds of infrastructure, including packs. This particular backpack design bears the name Langley, because its intended functions were composed to specifically address the needs of a trip to the mountain. The pack is designed to handle a full-size load for three days in the wilderness area south of Langley's summit. The pack would need to comfortably carry all my gear (personal and community) from parking lot trailhead to base camp in the alpine oasis of Cottonwood Lakes, and then be left at base camp on summit day, when we would be moving light and fast. The pack would need to be ready to be re-assembled in the field to utilize its secondary functions, although I knew going into this trip I would not be actively testing this aspect of the overall design. The main test objective was to determine performance of the primary function: carrying my load up and down the mountain.
One of the first things I noticed was how the pack handles a real load in a surprisingly sophisticated way. The load felt stable, contained, and was held comfortably. I did not weigh the pack it its fully loaded state, but the weight felt typical of what I am used to carrying on a three-day backpacking trip. In other words, the fact that I built this pack myself did not influence to underpack or overpack for my pack's sake.
The frame is easily categorized in the external frame genre, with its bamboo poles exposed and visible. As expected, all the benefits typical of external frame packs are available in this design. The frame's layered structure offers ample ventilation, and 36-inch-long uprights offer a generous loading platform. Yet, the fit of this setup, on this trip, felt more like the characteristics of an internal frame pack. It held a stable center of gravity low on the frame, and the bamboo foundation made for a flexible yet rigid suspension. So the overall feel of this pack was one of hybrid experience, a best of worlds scenario.
I appreciated the way the design allows for easy configuration of load. The bamboo frame is set up to accept containers, hard or soft, at tie-in points. In this way, equipment can be distributed into discrete compartments and then composed as load units across the pack's frame. This method makes possible the stacking of discrete items according to weight, accessibility, or any other criteria. These load units are exposed, and are therefore easily accessible, as load units, or as containers with content. What's great about this is that gear can be loaded and re-loaded according to needs dictated by influencing environments. It is easy to reload heavy items lower onto the frame to focus the pack's center of gravity. It is equally easy to open up a specific container to get to something in that container. This is probably one factor that helped the pack feel like it was behaving as both an external frame pack as well as an internal frame pack. I was able to quickly and easily re-configure my gear load, based on moment and need, as if I was working with an external frame pack or an internal frame pack.
The frame design at its essence is modeled on sandwich board signage, the kind one might see on a sidewalk, enticing passersby to step inside a shop. The pack frame, therefore, employs vertical poles to provide upright structure and shorter horizontal pieces to provide connective structure. The result is a frame that offers two distinct planes of outward contact, namely one plane making contact with the walker's back, and the other plane making contact with the load. These two planes become the two primary interfaces of the pack. On one side, the harness. On the other, what I have come to describe as the gear sled, the back side of the pack where equipment is attached to the frame through a series of tie-in points.
Then, in between these interfaces, or planes, is created a wedge-shaped container space. As negative space, this area increases ventilation for the walker, as would be typical with an external frame pack. As positive space, this area can be used to carry additional load. For most of this trip, I used the space to stow my smaller summit pack. The space worked well as bonus-load positive space. I found it to serve an equivalent function as that of quick-access pouches found on pack designs for sale in stores.
Another feature of this design is that the structure has an inherent desire to stand upright. Most packs want to fall over. This pack, however, has in its nature the infrastructure to stand up. When removing the pack and setting it on the ground, it is expected that the frame, if properly packed will find an upright posture, thereby helping realize the accessibility of the units loaded on the gear sled. This feature worked well in the field, although I can see how the amount of load would determine the shape of wedge needed to achieve a optimal natural stand. Also, since it is so easy to attach load to the pack, it is easy to pack the frame in a way that blocks its ability to stand.
The bamboo frame is bound together with a series of straps and cord, all common finds in backpacking equipage. Since the pack design is intentional, strap and cord usage is minimized by tapping holes and slots into the bamboo. This provides logical, structured, and efficient connection points. When preparing the bamboo pieces for use in the Langley pack, I brought them into my home workshop and made holes and slots with power tools. In this sense, the pack is a construction as opposed to an improvisation. This frame could, of course, be improvised in the field by harvesting branches and making connection points with classic lashing technique. I found the deliberate preparation of bamboo material into structure pack frame made the whole piece feel accessible and responsive as a tool, one with specific functions and methods of operation.
During design visualization, my theory was that as load units are attached to the frame's gear sled, weight would be directed downward to the base of the vertical poles. That is why I set up a unique tie-in point at the base of the pack frame, specifically to carry a rolled sleeping pad. Loaded and shouldered, the weight of the pack's carry is sent downward and then into the the sleeping pad, which essentially acts as a giant cushion to diffuse the weight of the entire load. This sleeping pad acts as a proxy to the waist belt, which under standard function is designed to distribute most of the weight of the pack to the base of standing elements in the walker's anatomy. I found this design element worked as theorized, and helped spread the pack load off the shoulders and into the waist. Also, I noticed that directing weight in this manner actually contributed to the pack's structural integrity. Weight channeling downward into the sleeping pad gave the pack an intentional behavior of pinching or clamping as a response to load management. That clamping action created a natural tautness across the pack frame, one that was proportional to the actual load being carried.
Overall, the pack did everything it was designed to do, and in performing to expectation, became a transparent component of the overall equipment lineup. Ultimately, equipment is effective when it performs function without drawing attention to itself, thereby allowing for the participation of activity in unique time, space, and company to be fully experienced. I traveled with two others, both of whom had various store-bought pack solutions. It felt like all three of us were able to handle the trail equally on par. I felt completely confident of my pack's ability to hold my load, help minimize onset of fatigue, and work with me on the more challenging sections of the trail. If anything, the bamboo backpack does turn heads on the trail amongst those who know what they're looking at. We had a number of fun conversations with other hikers who recognized this pack as some kind of custom setup.