David Bayer wrote:

>         You preload a spring by physically compressing it - by clamping
> down on it. Ok, let's look at it another way, the van has a preload which
> is determined by the weight of the van because NO OTHER LIMITATIONS are
> imposed on the spring - it's preload is determined by the weight of the
> van. Adding a spacer does not introduce any new limits to the travel of the
> spring at rest - there is no additional compressive force (if anything,
> there is an immeasureable reduction in the force applied to the van due to
> the fact that you shifted the center of mass away from the earth's center
> of mass which reduces the pull of gravity on the body of the van thus reducing
> the van's weight, again immeassureably) and thus there is nothing to change
> the preload of the spring...<<< >>>

> dave

 Last comment.  There is another limitation...the length of the spring perches.
If the spring is longer than the spring perches, obviously, you have to compress
it to make it fit even when no weight on the van.  Same principal applies even if
you don't have to compress the spring, but you do shorten the distance between the
spring perches.  With the shorter distance (i.e. by adding a spacer to loiwer the
top perch), at any given point in the suspension travel, the spring will be more
compressed than without the spacer.