here's one. it's aluminum angle, tig welded with a coroplast shell. you could probably duplicate it with-out welding by using nuts and bolts. there's a fork-mount made for the bed of a pick-up truck that holds the frame in place. if you want more construction details and pictures let me know. the thing about the bag is it's really narrow so when the support frame is in my wheels won't fit with-out taking the axles out.