Rory and I implemented the "twin flanking members" concept into the Solidworks database and created these animations of the frame morphing.
Here is an animated GIF. Click download to see the morphing action.
The nice thing about this approach is that the twin member design allows the frame to fold onto itself in the two extreme positions, thereby creating additional space for the seat and any seat adjustment mechanism.
Another animated GIF:
I would like to implement the adjustable gas shock into the model, and I will as soon as I can get the dimensional specs of the shock.
al