Basically an adjustable rack/shelf which would take the weight from large rucksack when cycling and ideally also when pushing. Attached to:
- bike seatpost
- luggage rack or it’s attachment points
It’s an idea I’ve toyed with for a while. I benefited from the effects when I had large rear panniers with a top compartment. The bottom of the rucksack rested on it and took the weight off my shoulders, leading to more pleasant cycling.