2007 LE 4x4 Crew Cab Long Box
So, by adding preload to the springs, I would gain more compression travel but I would compromise the static sag height that I have now that I like. Not to mention that I would also lose out on "droop" travel. I had it like that before but when I was driving over speed bumps and stuff like that, when the wheels fully extended, there was a not too nice clunk of the coilover fully extending and hitting the internal droop stop. I then decided to add some spacers made to the same height that I had the spring preloaded, then undid the preload. That gave me the same ride height but with the truck sitting more in the middle of all available travel as opposed to the top 1/4 or so.
It makes sense in my head but I'm not sure if I'm conveying this properly.
okay - some shocks are meant to travel x amount of travel and they are matched with springs to compensate down and up travel with a spring that allows x travel within a defined limit of movement. you buy a coilover that is designed for 2-3.5" of travel, you buy a spacer instead to keep the spring soft and don't preload the spring. the spring, shock, and valving are designed to be preloaded - the length of the shock cylinder, however, is desiged around the extended length of the cylinder. if you then travel the x shock 1/2 the length the spring was meant to travel it will 'pogo' or, 'top out'. it is designed to travel, lets say 3" inches, and you let it go 1" - therefore it 'pulls' the shockbody, causing an early 'bottoming out' feeling.
go to a budget bike with rear suspension in any store. hop up and down on it and feel the rebound and compression. now wind out the spring so loose there is no tightness to it. now hop up and down on that bike and feel it bottom. travel is one thing on a shock, but the maximum stroke travel is key. sometimes, preload is necesarry to spring length. period