is the foam frame removeable so you can...
is the foam frame removeable so you can use a sleeping pad as a frame?
No. The foam is not removable. Granite Gear makes a pack called the Virga which allows for this. It is an uber-light pack that doesn't include any suspension which allows the user to use whatever they want, like a Ridge Rest or Z-Rest, as the frame. The best thing about the Vapor Trail is that, at only 2lbs., it includes a complete suspensioned frame including duo-densities in the waste belt, shoulder straps, and backpanel. Compared to other ultra-light packs, the suspension on the Vapor Trail is very substantial.