Theres math geometry and what I call 'practical geometry'. Thats understanding the effects of leverage and angles plus the ability to simply think out how to design what you want or how to change something to do what you want. When I set up rear ends, I know how much travel I want, the dimensions of the shock I want to use compressed and extended. that gives you an area to work in, now all you have to do is figure out how to figure out how. How to think 'If I move this a half inch this way, what is going to happen?"
Like looking at the front end, take the shock off and measure the wheel travel, then take the spring off the shock, put it back on and measure the wheel travel.. If you figure out that there is an extra 2" of wheel travel available but your limited by the shock, then either get a diferent shock or movethe shock mount. On one bike I got a different shock (works 250r triple rate) AND moved the upper shock mount. I left about 1/4~5/8s" on the table at each end and if I remember right picked up a few inches of travel on a stock front end. and it handled better than a lot of bikes with extended a-arms.
