[RZR_Joe]

The top OEM spring in not a tender spring, it's just there to keep the main spring in place at full droop. You can add more preload to regain ride height. Just don't add so much preload that the main spring will go into coil bind at full compression.

 

[RZR_Joe]

Don't over think it

Preload is the amount of compression of an unloaded spring (fully extended).

Linear rate springs do not change the force needed to compress them throughout the compression cycle, hence "linear".

Adding preload simply sets ride height.

 

[RZR_Joe]

Initial spring rate the same but gets stiffer than before as it reaches suspension stops or bottoms out because of increased spring compression

Sorry but this is not the case, the spring rate of a liner spring does not change throughout the entire compression cycle. What you describe is a progressive spring in which the spring rate increases with the compression cycle.

Something to consider which has not been addressed is the motion ratio. If the motion ratio changes through the suspension travel it will effectively change the effective spring rate. One would need to model the suspension geometry to check for ratio change through movement. Sorry but it's not that important and this is not NASCAR 🤷‍♂️

 

[RZR_Joe]

For every inch you compress the spring you increase the resistance force. The more you compress the spring the more resistance force is applied. It's at the end of the travel you notice the spring change more than the beginning.

That's not how a linear spring works. I think you are confusing compression force with spring rate. Spring rate does not change on a linear spring no matter how far it's compressed.

Spring Rate (performancetrends.com)

What are linear springs and how do they work? (motioncontroltips.com)

 

[RZR_Joe]

The most accurate way is to set driveshaft angle to 14-15°.

I assume you mean axle angle and that is very much dependant on the, driving style, terrain, and machine. I've seen setups from -5-6 degrees to 30 degrees, all depends on various factors. Shock up / down travel is a better methodology. Not sure why people are so up up on "X" ride height based on GC, it's irrelevant. Just my 2 cents 🤷‍♂️