Originally Posted by
fredswain
I find it difficult to understand how wheel rate could go up as the shock is laid over further.
It doesn't. As you lay the shock over, you calculate a correction factor that is a decimel that reduces the spring rate.
http://performancetrends.com/Definitions/Wheel-Rate.htm
Like Fred said, don't over think this. Be aware that the angle changes things and how it does, but remember on an RC car with significant amount of wheel travel the angle between the spring and the arm doesn't remain constant throughout the travel, so the rate changes.