As mentioned in this topic I broke the plastic socket of the top ball joint and I ended up buying a replacement socket from a source that I think is a Strida distributor. I just received it this afternoon and have done the rerouting of the cable to string it back through the new socket part and I've inserted the replacement socket back in the frame.

But I can't get the ball to pop back into the socket. Sesamecrunch has pointed me to a video

http://ca.youtube.com/watch?v=p8yx8XsUPJw

showing it being done and I've tried that technique of setting the bike upside down and using the foot to press it into the socket, but that ain't working. anybody got any other ideas?