The Seek Outside Flight One is a ~50 liter, reasonably featured ~2.5 pound backpack designed to carry loads over 30 pounds well. Better load carriage and more coherent features than a Windrider 3400, and a burlier build than a Gossamer Gear Gorilla. In short, a modern lightweight backpack; an increasingly busy class, with the relevant reference point being the Rogue Pando Zoro, a point to which I’ll return in closing.
Unfortunately the Flight One combines a major design flaw with a major construction/patterning issue, the result being the carriage of the belt and lumbar pad not matching the other parts of the pack. I modified a Flight bag recently for a friend, following Philip’s mod detailed here, an easy job others may wish to emulate.
The Flight One uses an internal U frame, made from thin, solid aluminum rod, with a top piece of alu tube, that pushes on and makes it into a solid rectangle. The frame fits into a full internal sleeve, very tightly. This tight fit and the 7000 series alloy rod make the frame solid, springy, with an excellent degree of twisting flex. It’s a really nice solution to the modern pack problem. The problem is in the lumbar and belt arrangement. The belt comes in two halves, and adjusts for width with velcro. It velcros behind the lumbar pad, a la classic Dana Designs. Dana packs had a very stiff belt, and ran the main alu stay into the lumbar pad itself, both of which prevented sagging.
The Flight sags quite a bit, mainly because (as seen in the top photo) the lumbar opening is 3/4″ too large. As seen in the above photo, when I have 40 pounds in the pack, this slack hinges out immediately, effectively reducing the torso length of the pack by over an inch. In theory a 24 inch tall frame, the longest Seek offers on the flight, ought to be good for all but the tallest users. But that is a narrow if, and 22.5 inches is, for a taller but not beyond average person like myself, a fast problem at loads around 30 pounds.
Taking the bottom seam out and sewing the pad tighter would be one way to deal with that issue, but removing and resewing structural seams is a bit dodgy on relatively light fabrics like X21. Instead, my friend obtained extensions for the frame, and I removed the load lifter buckles and haul strap and sewed them 2 inches taller. A non-reversible modification, but simple and effective.
It’s illustrative to return here to the Zoro, which has had its issues, and takes a quite different approach to the belt-frame interface, using snaps to connect a hanging belt to the base seam, something quite similar to what Seek (re)introduced to the public with their original packs. Quite simply, I think this is the best way to go about building a pack, both because the connection methods tend to eliminate the possibility for stretch and sag, and because I don’t think lumbar pads really bring anything to the table in terms of enhancing load carriage (whether the lumbar benefits from different kinds of padding relative to the hips is a separate question).