dropped spindles?

dartley said

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.

Click to expand...

The spring rate is linear. Meaning the force required to go from 1" to 2" of travel is the same additional force to go from 2" to 3" of travel. The rate of change is the same.

Of course it takes more and more total force as the spring is pushed. Add the 1" to 2" force to the 2" to 3" force and you have the total force.

When we check spring rate for our circle track car we compress the spring set distance for every spring, then zero the force gauge, then compress the spring 1". That reading is the spring rate; pounds per 1 inch. (lbs/in).

It's just following the elastic curve on the materials tension graph. In the elastic region the curve is flat and the rate of change is constant.