- Fri Jul 18, 2014 8:36 am
#37729
That article is spot on. The "pre-load" does nothing at all apart from setting the ride height. HOWEVER, it makes a mistake at the end: it says that because the air spring is just a progressive spring, it does nothing magical compared to a progressive steel spring. This is wrong, because when you adjust the "pre-load" on the steel spring, you aren't adjusting it on the air spring inside. If you increase the pre-load on the steel spring, you raise the ride height, which increases the volume of air inside, lowering its pressure. In other words, raising the ride height REDUCES the spring rate from the air, SOFTENING the ride slightly. As far as I know the contribution to the overall spring force from the air pressure inside the suspension units is pretty small, which is why you would probably never notice the difference. What really bugs me is when PROFESSIONAL road testers regularly repeat the mistake that increasing the pre-load "firms up" the suspension. They are talking drivel, and it makes me wonder just how perceptive these guys really are, as opposed to being b***sh**ters.