Originally Posted by ???man
Many thanks to everyone for the replies.
I do learn a great deal for the post above.
Guess i have opened a can of worms
Suspension tuning is truly an art.
It's not a can of worms, but it is an art! Each element of a suspension system is of itself quite simple - mechanical levers, hydraulics, oil flow, etc. - but once it is all put together in one system it becomes complex.
I don't think anyone is saying that shock pressurisation is a bad thing, just that it is another thing. Go back to Dale's excellent post - what he's saying is that shock pressurisation will give you some dual rate, but that is probably not significant when compared to the spring rate.
Although YZRAndy and I will disagree about what happens when the shock damps the compression phase of the spring, it is the case that the more supple the bladder, and the less air is behind it, the more linear the shock is in compression.
If it were me, I would have the most supple bladder I could find, and some way for the air above the bladder to be let out when the shock compresses. That way the shock can move up (compress) as quickly as it needs to, and the less likely it is that the car will bounce over a bump. HTH