Reverse engineer rebound force from 'r-zeta target'. 'r-zeta target curves' are used to reverse engineer rebound force.  There is a wide variety of curves that can be used. Notice the blue individual 'r-zeta values' are not linear, starting at .99 and ending with .71 at 70ips. Look at 60-70ips for a quick snapshot of the overall 'r-zeta value'. In this case r-zeta value is around .70. For this example we simply reverse engineered the 2020 SEF F 450 rebound. This technique allows you to select a fork spring rate, the desired r-zeta target and calculate the rebound force needed. That doesn't mean the rebound is ideal, it just gives a solid starting point that can be incrementaly adjusted as needed.

Another example with the overall r-zeta value of .55 at 60-70ips. This r-zeta curve is similar to the one above and rebound force is about 20% lighter across the board.

This r-zeta target is lighter at 10-20ips than the example above. Notice r-zeta is lower at 10-20ips than 70ips. The rebound numbers are the same at 70ips, but dip at 10-20ips.