>>"Some may call it over building but I like a strong pack."<<
Well Said Terry. I couldn't agree with you more.
I have been working on a modular hybrid frame style backpack for over two years now. The hybrid frame is designed to carry everything from 5-50lbs and works with several different style packbags that range from a 20L day pack to an 85L expedition pack. The latest prototype hybrid frame weighed 30oz complete. That's the frame, shoulder straps, full wrap hip belt, buckles, webbing, and the removable 7075 aluminum stays.
So in its current configuration its pretty darn light but I would like to get it under 24oz without sacrificing the frames overall performance and durability. I have been looking into using different materials like woven Cuben Fiber and XPAC but I am really not sure they are worth it for this particular application but I really like both materials so its been really hard to decide. The VX21 Xpac is a nice balance of weight and strength with its 200D Oxford face. I have been thinking of using to this material throughout the entire frame including the back panel, front panel, outside of the shoulder straps and hip belt but when a 400D Packcloth weighs less then this material I almost wonder if its worth it to switch. I am having a hard time wrapping my head around how a 200D Oxford face VX21 XPAC would be more abrasion resistant then a 400D Packcloth. Any thoughts?
Oh and while I am thiking of it. I came up with a hypothetical woven cuben fiber. A 400D Packcloth with a CT5K.18 Laminate that weighs 6.0oz which is the exact same as a VX21 XPAC. Problem is cost. This material would be about 3 times as expensive as an XPAC and about 10 times as expensive as a 400D Packcloth but boy would it be burly. Might just be the perfect material :)