I hope these help. These are quick and dirty as I'm working in the shop, but get the overall idea across.
As Matt said, the forces sent through the links to the chassis are not tuneable with shocks and springs.
Calculating the actual force is irrelevant, as it is a function of the slope of the line of action and the square of ground speed.
The thing to remember: the faster you go or plan to go, it becomes more important. It also becomes more important the steeper the slope of the line of action.
With any design you have to compromise all aspects, and build for what's important for you, and where you are riding.
You have to compromise the slope of the line of action, with desired antisquat, pinion angle change, and ground clearance.
If you are moving stuff, you just do the best you can, to help all that you can for tuning the shocks.
Please forgive if my terms are generic and not the correct engineering terms.
I'm no engineer, just a hack in a dirty shop trying to keep up.
HTH.
