Bistiens are measued in Newton force. Fox has designated coding for valve stack combos that varry from 30-90 on 2.0" shocks and 30-120 on 2.5" shocks. An example is a 30 stock consists of all .008 shims while a 70 stack is .010 on top and .012 on bottom.
Others like King and SAW call out a stack based on each shims thickness, such as a 10 stack or 15 stack which is a stack of .010 shims or .015. Sometimes they will use an F in front of the number to tell you its a Flutter stack.
