Aus 230 is in the middle of a rebuild.

Cut the frame and moved the mast post back 50mm so that the center of the post is 1350mm from center of back axle.

I picked up a push bike frame at the tip for a dollar and decided to incorporate into suspension hopping that it will eliminate sail shake.
The parts have been tacked together and appear to work well and it is able to be stiffer or softer by adjusting the spring tension. May be others that are / have used suspension can share there results/problems.
Cheers
aus230