In Lenny and I’s opinion we think that a pack begins and ends with the suspension (frame, shoulder harness and hipbelt) this is the single most important aspect of a hunting backpack. It easy to change features of the bag by adding pockets, zippers, extra space etc; all you have to do is sew it on. Whats hard is getting a suspension design that will span the borders of being comfortable under day pack loads and maintaining its shape with 120lbs of horns and meat strapped to it. There probably isn’t a single pack on the market, hunting or backpacking that is harder to design than a superlight hunting backpack. It has to be durable, comfortable, functional and hold up to ridiculous loads.
We looked at nearly every frame concept on the market and weren’t satisfied with any of them. What makes a frame comfortable under heavy loads is rigidity, but that rigidity is what causes discomfort under lighter loads and decreases range of motion. With light loads you want a frame that moves and flexes as you hike, thus the reason internal frame packs have become so popular in the last few decades.
Can one frame do both? Can a frame be both rigid enough to support 100+lb loads effectively, while also providing enough comfort when only carrying the essentials? We think so, and we set out to design that frame.
We found our inspiration from the human body, we have a central support structure (spine) that carries our upper body weight down to our hips. Its extremely rigid vertically while still having a little flex in it to absorb energy. It also has the ability to rotate left and right as your body moves. The idea came up that we could make an very rigid frame much like an external frame but bring it inwards towards the spine. This would allow the frame to move and flow with the human body, while at the same time transferring the load on the pack directly into the lumbar -where it needs to be. The narrow frame would centralize the load towards the lumbar area, which drastically reduces fatigue on your hip flexors as nothing but padding touches them.
What material to use?
Our next issue was what material to use for our frame. We needed a material that was extremely strong but also lightweight. We immediately ruled out aluminum as we knew it wouldn’t be able to handle the loads with the design we had in mind. Our next option was carbon but we also ruled it out as while carbon can be extremely strong it can also very easily break if a load is applied in the wrong direction.
We then moved on to Titanium and upon researching the material immediately knew it was what we wanted to use. Titanium is incredibly strong and has the exact properties that we needed. It has an amazing ability to flex and move but won’t bend and won’t ever break.
So far our Exo Skeleton frame has proven to be extremely comfortable with day pack loads, while still being more than strong enough to handle heavy loads. (its been tested over 200lbs) This is possible because the frame is extremely rigid but still able to pivot around, allowing for freedom of movement in the hips; and not binding against every step you take.