True but with any suspension improvements, the costs for Sidecars become astronomical if you go for the CA Frames .
My Metalwork Teacher had a large Sidecar on his classic motorbike & two of us easily lifted it away from the cycle & turned it over when some rust needed sorting out . I was 16 at the time & I'd put it's weight at between 100lbs & 120lbs with wheel on ? No where near 200lbs or 350lbs . And of course an 8 Space Light Trike frame is only 300lbs ...
See my Cycles vs Trike thread for more rants on this subject :
http://forums.sjgames.com/showthread...=Cycles+Trikes