dropped spindles?

autoxcuda: "Spring rate is spring rate. It stays the same where ever you set the ride height. The amout you turn the t-bar adjuster (what you are calling preload?) just changes the ride height. Just like adding a spacer or turning a screw jack in a coil spring car."

Unless I misunderstand you - quite likely - that can't be true. With any spring the more you twist it, the more resistance it returns ... until it breaks. While a spring might be "fairly" linear in resistance for a certain spread, at it's lower limit it must be lighter and at it's upper limit it must offer greater resistance. Otherwise it would either constantly bottom out or break.