FWIW, Bike Friday's Tikit, is made to quickly fold, via
hinges for the steering and seat masts.
and when folded the front wheel extends in such a way
as It is used to roll along on it.
Same wheel/rim as Brompton, A high pressure 349 size..
Lots more component options , derailleurs or IG hubs, and belt drive..
3 sizes/top tube lengths.