Need initiation with REstackor PRO

I did some light suspension setup for friend but I want to going to a superior step. I working on something pretty hard for me, a 140 lbs riders with stock CRF250R 2012 suspension complain about a lot of bottoming. I try to convince him to go with lighter springrate and more agressive HSC shim stack. 


I also ever download the Restackor demo some years ago without understanding nothing to it, but now with more experience in suspension tuning I purchase the Pro version and I hope to be able to do something good with it.


If someone here can help me to getting started. I read all their website information but sometime I need more explanation. So thank in advance 



So first issue, I try to do my CRF 2010 stock valving stack, but I don't know where my mistake, but I miss a graphic and the valving stack deflection is so low



A couple things...


I doubt the fork shim ID is 1 mm which is what it's currently set to in the orange box (top left).  The reason the "shim stack" graph doesn't appear to have deflected much is because you set the force to be applied to the stack to 5 lbs (F.max).  This parameter (F.max) doesn't change the calculations as far as damping force or damping coefficient, it simply changes the range (x-scale) for the stack flow area and shim edge lift plots.  It also changes the shim lift plot, i.e. the apparent deflection of the shims at that force (F.max).


Similar to the F.max parameter, u.wheel sets the maximum suspension velocity that the software will make calculations to.  You have it set to 600 in/s, which I think is a little high (not an issue really).  When tuning my suspension for woods I set it to 200 in/s for forks and 75 in/s for shocks (due to linkage ratio).


Finally, the reason you don't see any data on the damping coefficient plot is because the y scale (range) is too small.  Right click on the y scale and change the max to say 10 and adjust from there to get the desired results.

OK so, what is a good range for tuning for MX track ?


Also why I get a empty graphic ?

Edited by DarkCRF

OK so, what is a good range for tuning for MX track ?


Also why I get a empty graphic ?


I don't know, you can set it to as large as you want.... All the u.wheel parameter does is calculate damping to higher suspension velocities and extend the x-scale (suspension velocity) of some of the plots.  So there isn't any harm having the value set high, but at the same time the suspension might never operate in that range so its pointless to look at it.


No graphic, like I said right-click the y-scale on the damping coefficient graph (right clicking the number "0.002" on the y-scale) and change the range of the scale (say the maximum to 10).  Are you familiar with excel and graphs?  If not, read up on google about graphing in excel is fairly straightforward.

Thank for help me fix the graphic


I try to figure out the wheel speed when someone overland a jump vs regular square edge bump



Also do you know a easy way to do a before after graphic ?

Edited by DarkCRF

I can't help you on the wheel velocity stuff, as I too am learning and there is a lot of conflicting information out there.  I doubt someone will tell you an exact velocity (i.e., 180 in/s).  You should think of suspension velocity in ranges, i.e., low-speed, mid-speed and high-speed and consider where those impacts fall into.  You said you wanted to add more HSC, come up with a stack, look at the results in restackor (confirming an increase in HSC), install stack in forks and see how it performs.


The easiest way to do a before/after comparison is with the "baseline" feature, its in a few of the restackor excel worksheets.  Once you understand excel and how restackor outputs the data, you can make graphs of anything you like.  For example (multiple comparisons):




I would advise you to read through the restackor manual

Edited by bmwpowere36m3

I try some stack and superpose graphic with photoshop, so I find it complicated, because in some graphic damping seen improve but in another one this is the otherwise 


Which one have the best HSC in this one ?


The aqua and violet is hard to identify because they are too similar










Edited by DarkCRF

It's hard to tell from your pictures, but in the last graph if green is "stock" than only the blue line is a stiffer stack.  Remember that this only the base-valve (BV) damping and the mid-valve (MV) adds a LOT of damping (progressively increasing with suspension velocity).  For example in the graph I posted, the solid lines are BV only and the dotted lines are BV+MV damping.


Is d.bleed (clicker bleed orifice) really only 1.5 mm in diameter... seems super tiny.  That's why there is such a huge spike in damping at the very low speeds (under 10 in/s) and the reason the dotted lines for open/closed clicker settings are barely any different from the "setting" (i.e., very little adjustment range).


If you want bottoming resistance, I think it would be better to change the MV stack or add oil to the forks.

How you can match BV + MV in the same graph, this is a Excel Pro magic trick or I suposse to get this option ?


For the dbleed, when I dissembly my fork for take mesurement i realize too late I forgot some like d bleed, stack ID diameter and w seat, but I try with a 3 for d bleed and the clicker range is greatly better. 


For the shock piston, I imagine I must use the midvalve key ?


Thank a lot for your help, this greatly appreciate and I feel most confortable with the software

To get mid-valve damping and combined mid-valve/base-valve damping you use the excel spreadsheet called midvalve.  You enter the base-valve data into the BVc tab (run it and load output) this will produce plots with only BV damping, mid-valve data into the MVc tab (run it and load output) this will produce plots with only MV damping and finally you enter data into the plot tab (things like suspension stroke, oil height, air pressure, ICS, bladder info) this will combine the BV and MV damping into plots.  Read this:


D.bleed I would think is around 2-3 mm (but what do I know).  You need to measure the orifice diameter in the base-valve assembly. Shim ID (for forks BV) is probably 6 mm and wseat seems reasonable at 1 mm.


Shock piston, as in the rear shock absorber?  Then yes, you use the midvalve spreadsheet and enter data into the MVc tab.  The compression adjuster on the shock would be the base-valve, but I haven't found a way to model that.  So I only look at the mid-valve damping for comparison sakes.

Edited by bmwpowere36m3

I gonna try some this week an come back with new question


Your help is really aprreciated thank a lot again

Thank for help me fix the graphic


I try to figure out the wheel speed when someone overland a jump vs regular square edge bump



Also do you know a easy way to do a before after graphic ?


There are probably a hundred different scenarios for trying to figure out wheel speed. Here is a simple one for a wheel rolling over a bump.




So....... If you took 30 mph as some practical MX speed and bottomed out your fork from the race sag position (~9" travel) the wheel speed would be around 350 in/sec. I think BMWpower mentioned a shock shaft speed would be about 1/3 once you account for the shock linkage, so something in the 110 in/sec range for a shock.


BTW: There are other plots around for 18" and 19" wheels, just didn't have one handy. 


For landing a jump the free fall time can be figured out from how far you fall:   x=1/2 a t^2

doing this in feet and seconds for a 10 ft fall works out to t=sqrt(2x/32.2)  => 0.788 seconds free fall.

and the impact velocity would be u=at;      u=32.2*0.788    => 25 ft/sec  => 300 in/sec.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now