Perfected? That's a big claim. Maybe I'm going too far. Perhaps there's room for improvement.
But I doubt it!
But, in any case, I'll lay out the parts needed here. In case anyone wants one for themselves.
I'd recommend this particular saddle. http://www.amazon.com/gp/product/B00...ilpage_o00_s00
I've experimented also with the Cloud 9. And it works. But this saddle seems much more apt to this job. The front hairpin spring certainly helps. Plus, on this model the 'seat pan' is also suspended by a criss-cross of narrow extension springs. Almost hammock fashion. So this saddle already has some 'bounce' to it. IMHO, it's superior to the Cloud 9.
Remove the rear springs plus the posts that mount them.
Detach the main undercarriage from the front hairpin spring and flip it over.
The bolts that held the old springs on are not going to be long enough for you. I replaced them with these.
Memory tells me that they're 5/16 x 7 in. But they look longer in this pic. I should have measured them. But you'll have some wiggle room on this project anyway.
Your new main rear springs will be two hairpin style springs. http://www.amazon.com/gp/product/B00...ilpage_o04_s00
Those hairpin springs don't have the reach needed for this job. So supplement them with coil springs.
These particular ones are cheap and easy to work with. You can experiment all you want with length.
Darn! I've reached the limit on photos. I'll have to do a 'part 2'.