Disclaimer: I know this is an ultra light site; I've had a subscription for a few years.
I own an ultra light, and a medium weight pack. I also own an osprey crescent 75 – which tore me up last year. My goal was to borrow ideas from many commercial packs and make an "everything" modular pack that I could take on various SAR missions. I could have the modules pre-packed and just zip them in and go. I wanted the pack to be no higher than the middle of my noggin' and ride better on my hips than an internal. I used inspiration from the Mystery Ranch – "crew cab"; the Eberlestock – "just one"; and a friend's custom military style bush pack. (my cost was about 1/5th as much)
I used a kelty cache hauler frame – cut and modified – and made zip-together modules with modified molle webbing. There are 6 one inch buckles that can be used for compression straps or other packbag attachments (I intend to make a flatbed in the future)
My pack came out weighing 1 Lb 3 Oz less than the osprey (in the 3 tube configuration) and a hell of a lot more comfortable to carry.
Three tubes plus small daysearch pack in inner cavity:

started here:

two tube:

Two tube + 50 L dry bag:

2 tube + double tube:

2 tube + double on outer zipper:

Base pack:


side view:

This is my prototype, please shoot me your ideas. I've had it in the field on one SAR and I am very happy with the performance
Enjoy,
Dave



one piece of fabric folded to make 4 tubes


