Originally Posted by jur

I made some super-imposed pic of the Helix vs my Ti Swift (medium-large) and a Brompton pic I found somewhere on the web.

The pics were placed such that cranksets would match position but not height; height was determined by the wheels. The idea is that if the crankset determines everything else, you can see where the handlebars and saddle end up. That should tell you something about the Helix geometry.