I found thigh strap placement of Tim’s likewise my preference, but there is a benefit of a third location directly to the knee making the shape of the straps a triangle, resulting in a stroke much more responsive to the whole body of the boat as well as the force distributing over the fabric (avoiding a leverage stress). I uploaded some pictures and a video:
This looks cool. I have been thinking of something similar but with all those straps enclosed in fabric to reduce foot entrapment and to spread the load out.
At a packrafting and kayak polo session (they go on concurrently) I could only practice rolls between the two games (cause I’m fixated). Afterwords a kayak friend got in and rolled and said he’d like knee cups rather than thigh straps, so I am now thinking of sewing fabric to the straps on one side and then gluing the fabric to the tubes on the other side so that
(1) there will be no straps to entrap you as they will be attached to fabric that is then glued to the boat (i.e no loops)
(2) these will be knee/leg cups (no doubt shaggy’s could come up with some other cool word for them.
(3) they would distribute load onto tubes
It is nice to be rolling my boat in these warm Fiji waters right now.
Good to see people trying different configurations. The main reason I place the straps further back next to the air valves is because this helps hold your butt down on the seat. If there were nothing but knee cups, your butt would become detached from the seat, making your more disconnected from your boat & putting your head deeper underwater exposing it to more risk. If knee cups are used, than the next step would be to make inflatable hip pads that hold your butt in the boat, just like kayaks have. I almost glued inflatable kayak hip pads into the sides of the packraft, but found I didn’t need them as long as the thigh braces are mounted as far back as I mounted them.