Last month a reader contacted me about a pack bag for a Seek Outside frame, mentioning these bags as inspiration. Primary use for the pack would be elk hunting in the Olympics, with capacity and simplicity as main design priorities, along with side pockets which would hold a sizeable tripod and 80mm+ objective spotting scope. After some discussion, we agreed that I’d try to thread the needle and make side pockets which could both hold these hefty optics, and provide on the fly access to water bottles, backpacking style.
This was a enjoyable project, being in essence the 6th or 7th refinement of a set of dimensions I’ve settled on as ideal for an expedition pack, while tweaking features and materials based on experience. Hunting, and then packing, elk in coastal rainforest is one of the more demanding activities I can imagine in terms of pack durability and weatherproofing, making the excellent X50 tactical fabric (in ranger green) an easy choice. In the tactical series the x-ply is a kevlar thread, and far flatter than the traditional dacron, in theory removing it as an abrasion point. Is does add tear strength, though I can’t see this being useful in the field given the toughness of the face fabric. The base reinforcement is 500D Cordura, and wraps up the top a few inches for max security while sliding down talus and alder thickets.
Side pockets are 500D Cordura, and 20 inches tall on the front face. They attach to the uppermost compression strap, and are fully dimensioned with square bases, 5 inches deep on the front edge, 4 inches on the user edge. I don’t own a big eye, but as seen below they swallow two 48oz nalgenes with room for at least another, when the main bag is crammed full.
Bag dimensions are almost identical to the packs in the bison post; 42 inch lower circumference (8 inch depth), 50 inch upper circumference (12-13 inch depth), and a 40-42 inch unrolled height against the user. This large amount of upward taper makes the ~90 liter at full height bag more like 55 liters when rolled all the way to the top of the frame. This makes a smaller load less floppy, and enhances carry in meat shelf mode, as the lower part of the bag can’t get cantilevered that far out from your back. The customer asked, in response to my commenting that this was a moderately large bag, what one could do to make a pack even bigger. A lower circumference approaching 50 inches would add a huge amount of volume, and you could certainly make the bag taller, which I’ve never tried. Presumably even with stiff xpac fabric and a roll top, at some point you reach a literal tipping point where stability goes downhill. With Seek frames you can stack extensions, and a custom job on a 30 inch frame could probably get close to 50 inches without issue, in the process truly getting into bivy bag territory.
Truly custom pack building is the most satisfying type, as well as the most nerve wracking. Perhaps with enough experience I’ll cease to worry so much about meeting expectations with brand new designs, though at that point the fun level might decline in tandem. For the moment it’s hard to resist adding a personal anxiety tax each time I agree to such a project.
And hey, it’s September. Time to go sheep hunting (in only a few days). Almost sad I won’t be getting this bag dirty myself.