On Jul 27, 10:14*pm, Brad wrote:

ya know, that is a pretty cool looking contraption, but from a
homebuilder point of view, making it out of aluminum tubing, extrusion
and flat sheet is much easier and less labor intensive. might be a bit
heavier, but not much. of course the wing cuff would be composite!

Actually, the carbon has some pretty compelling advantages. It is a
lot lighter, so that it is easier to stow, carry, and attach.

I think that carbon sleeve over EPS or EPP rod would indeed do the
trick for the arm. If you were serious about it, you'd have a high-
pressure female mold, and mold the part by inflating a plastic bladder
inside the sleeve material, but the male molded part would be almost
as stiff and easier and cheaper to make for just one or two.

As Dave points out, it can be made springier, so that the goofy steel
spring and shock absorber isn't required. The way it grabs the axle on
only one side of the wheel is a neat trick, but the greater bending
loads makes the axle heavier than if the arm were forked.

As Andy points out, the leading arm might be divergent, but I don't
think that it is actually unstable except at very high speeds and
loads.

Thanks, Bob K.