I, too, have a motorcycle suspension background, only with motocross. The sort of things I think people need to understand when it comes to shock tuning might get deeper than the typical range of adjustments I see offered for sportsman-level suspension components. Stuff that comes to mind includes...
Compression
- Low-speed circuit
- High-speed circuit
- Common characteristics applicable for Off The Shelf (OTS) dampers
- What the "ideal" compression curve(s) would be for different types of applications
Rebound
- Low-speed circuit
- High-speed circuit
- Common characteristics applicable for Off The Shelf (OTS) dampers
- What the "ideal" rebound curve(s) would be for different types of applications
Tuning high- and low-speed circuits independently
- External adjustments (a.k.a. "clickers")
- Internal adjustments (a.k.a. re-valving)
Static / loaded ride heights
When you want more travel vs. when you want to limit it
Understanding how spring rate needs to considered separately from damper settings
Difference in suspension behavior when using softer spring rates with more preload, rather than stiffer spring rates with less preload
Well, it's a start.