Hello folks,
I'm building a lightweight convertible backpack/suitcase pack for travel, with serious suspension for long walks or even the occasional hike or two at destination, but sleek in looks as well so that I could saunter into conferences with it. I subscribe to carry-on/one bag only travel to keep things cheap, fast, and headache free, but it is very apparent I will be asking a lot of this 22 x 14 x 9 inch box as a result. A fun challenge.
This will be a rather long build for sure, so I'll be updating this thread periodically. First off, I'd like to solicit commentary from the community that knows how for the initial design.
Laptop compartments use up a lot of volume and weight, what with all the integrated organizers and exterior zipper going round the whole of the bag. I'm thinking of reducing the laptop compartment to a camelbak-type pocket accessed through a zippered slit on the top of the pack, the computer to be kept in its own neoprene sleeve. This I think would keep things reasonably accessible, especially at airport security.
For protecting the suspension, I'm going with a zippered fabric panel rather than hide-away straps/hip belt because I would like to protect the back panel as well, for occasions where the bag is put under trains, planes (the dreaded gate-check), and buses. I rather dislike the tuck-away panel, however, because it involves a large amount of zipper, and it isn't very neat, usually involving a hook-and-loop secured pocket on the filthy bottom of the pack. If anyone has experience with a better strap/hip belt hide-away/protection solution, I'd like to hear it.
I do have occasional access to a vacuum bag, so I may try my hand at forming my own frame sheet. My expertise is limited to wood veneer. Any suggestions for composite materials?
Finally, anyone know where to get VX42 fabric? Heavy I know, but I like its stiffness, and it is apparently significantly more durable than VX21.
That's it for now. Thanks for taking a look.

