Pressurization inputs are on the "Plots" or "Res"
tab of ReStackor spreadsheets.
Height: Max stroke depth and shaft speed for ReStackor calculations of
the combined base and mid-valve damping force
Oil viscosity, density and temperature used in calculations
Bladder, Fork: Parameters describing the configuration of
reservoir pressurization systems in ReStakcor calculations.
you click on the "MV_Analysis" macro button ReStackor runs a
set of calculations to determine the combined damping force of the
base valve and mid-valve. Those calculations are run up to the shaft
velocity specified by Rod Speed and up to the stroke depth specified
[=] Bladders, ICS systems and the gas pressure in open chamber forks
all depend on stroke depth. ReStackor calculations start with the
suspension at full extension and integrate over the stroke up to the stroke depth specified by Lstroke. Lstroke specifies the actual shaft
stroke of the shock, not the wheel
Speed [=] Maximum suspension velocity. ReStackor
computes the combined compression damping force of base valves (BVc) and mid-valves
(MVc) up to
the shaft speed specified by Rod Speed.
Oil properties used for all calculations in the spreadsheet.
[=] Shock absorber oil temperature in degrees Fahrenheit. Temperature effects on viscosity are
evaluated in ReStackor using the Andrade
relationship along with companion relationships for the oil density
change with temperature.
[=] Oil kinematic viscosity in centistokes at 40 centigrade [cSt@40C].
[=] Oil kinematic viscosity in centistokes at 100 centigrade [cSt@100C].
[=] Oil specific gravity or density in g/cc
[=] Reference temperature of oil density spec, usually at 15 or 20 deg
specific gravity of suspension fluids range from 0.80 to 0.95 with
synthetic fluids at the higher end.
Gas pressurized bladders
and Inner Changer Spring, ICS, systems
are used in shocks to pressurize the fluid for suppression of cavitation.
Open chamber forks also use the gas pressure buildup as a spring force for bottoming
control. The frames below define ReStackor parameters
used in each system.
models gas pressurized bladders and ICS systems in forks and shocks.
ICS inputs specify the spring stiffness, float and piston
diameter. To run an ICS configuration all of
the bladder inputs must be set to zero.
[=] Stiffness of ICS spring; [ kg/mm].
[=] Number of coils in the ICS spring. ReStackor uses the
number of coils and wire diameter to determine the spring coil bind
length and travel of the ICS piston. Push the piston beyond that point
and it is going to crack. The fraction of ICS stroke
used is reported in the ReStackor output as Nics.
[=] Wire diameter of ICS spring; [mm].
[=] ICS spring float at full suspension extension; [mm]. This
parameter specifies the ICS piston motion necessary to engage
the ICS spring. Negative values of FLTics preload the spring.
[=] ICS chamber length; [mm].
[=] ICS piston diameter; [mm].
[=] Shaft hole diameter in ICS piston; [mm]. For a typical
configuration the base valve support shaft passes through the
ICS piston. This parameter specifics the shaft diameter and is used to
determine the pressurized face area of the ICS piston.
[=] Pzero in the Fork section defines the bleed pressure at full extension of the suspension; [psig].
an open chamber ICS that is vented to the fork gas chamber the
of Pzero, Loil and Ltravel defined in the Fork section determine the gas pressure acting on the ICS
piston as the fork is compressed.
For a closed chamber
ICS system the gas pressure above the ICS piston at full extension
is set by the Pzero input in the Fork section. This initial
as the ICS piston compresses gas in the closed ICS chamber defined by L.ics and
D.ics, but is unaffected by compression of the fork gas volume. To model a
value of Loil and
Ltravel in the Fork section must be set to zero.
Configuration: Specifies the reservoir bladder configuration used in a fork or shock. To run a bladder configuration all of the Fork and ICS
inputs must be
[=] Initial bladder pressure at full suspension extension; [psig].
[=] Bladder length; [mm].
[=] Outside diameter of bladder; [mm].
[=] Normally zero. For a fork, the bladder may have the base
valve support shaft running through the bladder. ID.blad is the diameter
of the shaft for use in computing the gas volume in the bladder; [mm].
"Fork" input block defines the initial bleed pressure and oil height
with the fork at full extension. To run an open chamber fork all ICS and Bladder inputs must be
The value of P.zero specifies the initial fork pressure at full extension
for both open and closed chamber forks.
[=] Initial bleed pressure of fork at full suspension extension; [psig].
[=] Oil height in fork measured from top of fork tube with the fork fully
[=] Length of fork travel; [in].