Sample Apps

  XR650 Tuning

    Input file

  Shim ReStackor

    Clicker map

    Valve Tuning

    Trail Stack

  ReStackor pro

    Clicker map

    Valve Tuning

    Damp Coeff



ReStackor pro Valve Port Diameter Calculations

The input file for the XR650 ReStackor calculations was setup here. The first thing is to create a map of stock clicker settings vs damping rate for the stock valve stack. The clicker map is created here.

To determine the effect of different valve throat diameters all we have to do is change the D.thrt parameter in cell H8. The stock valve port diameter for 2000 to 2004 bikes is 2.65 mm. Borynack reports that the 2005 XR650 is using a port diameter of 1.96 mm. We want to run both of these diameters and the 3.64 mm port diameter used by Borynack to determine the point where the valve port diameter limits the flow. For the first calculation we will run the stock 2.65 mm throat diameter as setup below.

After clicking on the run button and the Load_Output button the ReStackor calculation results are loaded into the "ReStackor" tab of the spreadsheet and the plots are automatically updated. 

ReStackor Output

Results from the calculations are loaded into the "ReStackor" tab of the spreadsheet when you hit the "Load_Output" button.

Results from Shim ReStackor calculations are in columns A through E and columns G through M contain results from ReStackor pro calculations. The values in the output field are:

  • Shim ReStackor Output

  • Force (column A): Force applied to the shim stack

  • Yedge (column B): Edge lift height of the shim stack

  • Aclsd (column C): Valve flow area with the clickers closed

  • Aclk (column D): Valve flow area at the clicker position specified in the input file

  • Awo (column E): Valve flow area with the clickers wide open

  • ReStackor pro Output

  • Uwheel (column G): Suspension velocity with clickers at the set point defined in the input file

  • Uwo (column H): Suspension velocity with clickers in the wide open position

  • Uclsd (column I): Suspension velocity with the clickers in the closed position

  • Gv (column J): Oil flow rate through valve in Liters/min

  • Fstack (column K): Force applied to shim stack by fluid flow

  • Force (column L): Damping force produced by shock

  • Pressure (column M): Pressure difference between valve face and fluid reservoir

Valve Port Throat Diameter Effects

For this exercise we want to compare a couple of cases with different valve throat diameters and plot the results to determine the suspension velocities where the valve throat begins to limit the flow. On the ReStackor spreadsheet every time you click on the Load_Output button the data columns in the "ReStackor" output tab are overwritten. To save results between calculations we need to copy the outputs from the ReStackor tab to another worksheet.  

To do this a new worksheet tab named "D.thrt" was created and the ReStackor pro results copied to it. Subsequent calculations with the throat diameter set to 1.96 mm and 3.64 mm were made and the results pasted into the "D.thrt" work sheet. With these results the effect of valve throat diameter was plotted as shown in the worksheet below. 

The instructions here assume you are familiar with excel and how to run and manipulate data within spreadsheets. The instructions do not go into how to create a plot in excel. If you need help with that check out the microsoft excel website. 

RETURN to XR650 sample case.