If I recall correctly (it's been a long time since I have seen one), the Slingshot uses a cable for the downtube, to some suspension effect, or "slingshot" effect. They were kinda gimmicky when they came onto the scene (mid 80's), and while they were enjoyed by many and had a bit of a cult-like following, they didn't really catch on for very long. Also, and maybe more importantly as far as your question goes, I do not recall that they are meant to be broken down (as is the point with S&S couplers), nor do I think it is even possible, as you need to top tube to separate as well, and that is not the case with that bike.