That misnomer - Sliding Pillar...
snip
There is an excellent article in an edition of Uncle Melvyn's magazine, The Morgan World, by Peter Ballard. Bit of a suspension guru is Peter. Riding in his 4/4 CVH is competely different to my unmodified '76 4/4 (with its falling rate setup).
Cheers,
Thanks Graham, I found the article very interesting. Here is a link to a version (I assume it is the same) published on Morganatica
http://sites.google.com/site/morganatica/suspension/main-rebound-spring-interation