Another coilover question. Triple rate?

[sled_dog]

What does the third spring do? I've heard it called a "tender coil" and from seeing them on rigs, it looks like they do little to actually suspend the vehicle but just keep the others in place on full droop. Am I right in that assumption or am I making an ass out of myself? Is there really an issue with springs coming unseated under heavy droop?

 

[ntsqd]

The Tender Spring keeps a little load on the lower spring cup so that it won't bounce up and off the step on the lower eyelet when the shock is fully extended. Only need it if full extension allows the springs to go slack. If the preload nut is screwed down far enough you don't need them, but that sometimes is not the best compromise.