As an initial set up, my Riese and Müller dealer recommends a psi pressure of weight in kilograms plus 10%. This is also equivalent to a psi pressure of half the weight in pounds.I actually don't think so. Just as a coincidence when using pounds and psi it turns out that fork pressure as a good starting point happens to come out to a number half of the rider's weight. I weigh 180 lbs and a setting of 90 psi sets my sag perfectly. With the shock it works out again by coincidence. If I set my shock to 180 psi the sag comes out right. Its just a matter of numbers, its not a real "ratio". I'm pretty sure that is what he was referring to as it is a commonly acknowledged rule here where we use lbs and psi. Anyway, lets see what he says he meant.
Marc
180 lbs = 180 ÷ 2.2 kg
180 ÷ 2.2 plus 10%
= 180 ÷ 2.2 × 1.1
= 90 psi