Originally Posted by
chaadster
I think that is the best advice for the OP (if the security need beyond a frame lockup exists). Simply folding the main frame hinge should work to capture both wheels with the right lock.
On my Dahon I use a lightweight TiGr lock strapped to the boom. It's easy on/off, and long enough to do the fully folded lockup when needed, and no lock is lighter:
Ooh, how do you find the TiGr lock? I had my eye on it when it was on KickStarter, but I concluded that it might not be flexible enough for locking to random objects. I'm also not too keen on having things strapped to the top tube.