White House K10 - a story of regeneration

[Tev62]

But once you are sitting on the bike and your weight has overcome that initial force, where the preload is, is now irrelevant. Dropping the preload has dropped your front end a little, reduced the trail a little and might make the handling a little sharper but it should have no effect on damping. The damper will be doing the same work, it has not picked anything extra up from the spring. A great read on suspension is Race Tech's Motorcycle Suspension Bible, a small excerpt here on preload. It goes into more detail than this and is a great read if that's your bag.

"Spring preload is one of the most misunderstood concepts when discussing
suspension. Often we hear riders talk about adjusting their motorcycle’s
spring preload to make the spring stiffer or softer. This is a misconception:
changing spring preload does not change the spring rate at all. The spring has
the same rate regardless of how the preload adjustment is set.
Let’s look at what really happens. When a spring is installed in either the
front or the rear suspension, the spring is typically compressed a small
amount. The length the spring is compressed is referred to as preload.
Specifically it is defined as the distance the spring is compressed from its free
(or uninstalled) length to its installed length with the suspension fully
extended, Most vehicles, including motorcycles, use positive spring preload
(negative preload means the suspension compresses before hitting the
spring). This is true even for bikes that don’t have external preload adjusters.
Even suspension with the external preload adjusters backed out all the way
commonly still have some preload".

"With a given amount of preload force on the spring, it will take that same
force to initiate suspension movement when the suspension is fully extended.
As preload is increased, it takes more force to cause the fork or shock to
begin to compress. When preload force is decreased, less force is required to
cause movement. It is important to note that when the motorcycle is resting
on the ground with the rider on board, the suspension is compressed. When
preload is changed the sprung mass is held higher or lower. This means more
preload does not require more force to initiate movement once the weight of
the bike has compressed the suspension".