Re: I See Springers...
If I might suggest--Take an old front fork and turn it backward. Make a pair of bottom pieces to carry the axle with shoulder bolts for pivots. Whack the stem off a Schwinn blade fork and mount a horizontal clamping table atop it for a blade spring (coming from the backward main fork where the fender would normally attach) It would resemble an Indian fork from about 1937 and shouldn't weigh TOO much. There are places that custom build leaf springs for trailers, etc. that should be able to furnish a 1" X 1/8" blade that would be a good starting point and shorter pieces can be added as necessary to adjust the carrying capacity/action. (as opposed to actually engineering something. It's called Edisonian engineering.) Keep trying until something works. The longer the better for good travel. KW