I was looking through my old Bicycle Motocross News papers and found a couple pictures of these in the "Christmas Gift Guide" from 1975. I searched here and found a thread that Cash had posted asking this same question back in 06. Nothing materialised from it. Maybe things have changed in a few years.

I do remember these from BITD. It seemed they were trying to bridge the gap from 'shocker' bikes to rigid frames. Interesting idea, but I can only imagine the outcome of the flex factor at the 'rigid' pivot point behind the bottom bracket. I am wondering if any of these survived to the present day?

Wow, that's cool. I live down here in Trailmate territory and I don't ever remember seeing those.
That fork looks like a 1975 version of an Answer fork.

I don't know anything about it, but it's cool! Sort of Matthews-ish, don't you think?

Scott, funny you should mention Matthews. This is from the same 'Gift Guide'. Check out the "Full Loop" Matthews.