After David Chenault inspired me with his Spring Skis, I tried to make something similar. I failed, but my brother succeeded.

He has now written a high resolution document and a low resolution document describing the bindings. Enjoy!

Nice work, and nice write up. I'm slowly working on a much improved v2 of mine. No rush, as I won't need them until May.

Ross,
Are you familiar with what were the Ramer bindings that readily accepted many hiking boots and had a toe release. Would be interested in your opinion.

I'm not familiar with Ramer bindings. I've only seen them on the web. I seem to remember some site that listed several approach ski choices, and those might have been on there. Can you buy them now? When I started building my own, I knew of no one making anything that interested me (Yupi and Karhu stopped making theirs). Now, there are the three offerings I mention in my little doc (although one of them is only a ski, which really doesn't count, since there are several little skis, or skiboards that can be used). Unfortunately, unless they still make Ramer bindings, I don't think anyone makes anything that would really fit the bill (without making your own).

I have Berwin bindings (white Canadian Army ones) that I attatch to my Voile' release bindings.

My solution for more stiffness was to add (pop rivet) a layer of stainless steel 1/16 inch strip inside the Berwin's sole. It helps but ain't nearly as stiff as your setup. Nice solution you've worked out.