thanks johnellison, i'll give that a go. wish i hadn't sold on the soft spring
and thanks b45her, but i don't agree.
they are linear but that line is not horizontal on a graph so to speak.
it still takes more force to compress eg 10mm near the end of the stroke (when the spring is more compressed) than near the beginning.
from another forum:
the red line is a linear shock, the blue a progressive.
'X axis would be how far into the stroke you are and Y axis being how much force needs to be applied. All shocks, no matter if they are progressive or linear, need more force to compress them the farther they go into their travel'
that means johnellison's trick with a spacer would work because the spring is already more compressed at any given point in the travel than it would have been otherwise, requiring more relatively more force than before to move the same part of fork travel.
[and that is why preload affects sag.
the spring can be made more or less compressed at a given point in the forks travel or conversely, with a given force acting on the system, it can be made to move more or less depending how far through it's compression the spring is.]
anyway blah blah blah. that's my understanding of it.
but it's got me wandering how far you can space before the spring becomes fully stacked before full travel. not much danger of that i'd guess...