Thank you, blueeagle for that "creative" suggestion
we would be interested to hear why.
My mind boggled for a day or two after you posted. A sidecar on a Duke
My (preboggled) mind is imagining a light frame for the sidecar (titanium?) and a replica Stieb s/a chair made in say, balsa with tissue paper covering. the whole enchilada should be 2 or 3 pounds total weight (without a wheel) Perhaps the wheel could be non-rotating with either an anti-gravity fitment to keep it up or a hover-pad.
Not by me, I fear.
Triangular tyres (that's Tires to you) and featherweight frame and forks would not translate well for sidecar use.
andrew