Time for another attempt to address nagging pack discontent. I put together a quick and sloppy prototype with some WX20 pieces with the intention of trying to address some shape questions (especially regarding side panels) that I’d been thinking about throughout the summer. Dave’s well-thought-out pack further piqued my curiosity.
Finished dimensions are ~ 11″ (back) x 7″ (Sides) x 9″ (front) x 38″ tall. Pack will have twin flat aluminum stays.
First experiment was shaping the side panel directly from a stay from an existing pack that fits my back, with the extension collar continuing at the angle from the top of the shoulder towards the head.
This actually had the opposite of the intended effect. The problem with this profile is that when the pack is full and the back panel is no longer flat, the load actually ends up further from your back than if if were straight due to the curve in the middle of the back. It might work with a rigid backpad or framesheet that extends the entire width of the back panel.
Round 2: Side panel is straight until roughly the bottom of the scapula, where it then angles towards the head of the wearer and continues the rest of the length. Below, verson 1 is on the left, v2 on the right. The curves on the v1 pack above are actually a bit more aggressive than the white pattern below.
This carries far better than the first iteration and keeps the center of gravity much closer to the back. The angled top makes a huge difference in carry compared to a totally vertical profile.
The other experiment was cutting out a curve at the bottom of the front/bottom panel with the idea that it would help the pack hug the lower back. This worked remarkably well. I have the hipbelt anchored only about 4″ apart and the bottom of the pack follows the contour of the belt for the entire width even when full and without a ladderloc/webbing attachment to the hipbelt. Rough pattern:
to be continued…