Wow! I like your ingenuity! Looks strong enough for not too strenuous riding. Regular inspection of those tubes for cracks should be fine.
Just a side observation: Going by your motorised transport, you aren't strapped for cash. So you could consider on of the higher quality folders for dual duty... Bike Friday, or Pacific Reach comes to mind. Or the new Dahon Jetstream.
Thanks for your comments. It has nothing to do with money. I just like to build things when I can, automobiles and motorcycles excluded
I don't require 30 second assembly, only small enough folded size for the trunk of my car.
I'm familiar with BF, Dahon, etc., but I wanted a full size bike for the workout riding I do. In fact, the Dahon Matrix was in part a source for my own simplified design.
Rita and I ride a Trek tandem. Here's a pic from yesterday.
Tom
http://www.yostwerks.com/ - My free folding kayak building manuals