Home
Basic Dirt Bike How-To's - Video
Dirt Bike How-To's - Video
Living The Moto Life - Video
Bike Tests | Shoot-Outs - Video
Forums
What's new
Latest activity
Log-In
Join
What's new
Menu
Log-In
Join
Navigation
Install the app
Install
More options
Close Menu
Forums
MX, SX & Off-Road Discussions
Dirt Bike Mods & Maintenance
Rocky, rooty trail settings.
Reply to thread
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Message
[QUOTE="James Dean, post: 24622, member: 18501"] MN KDXer, I agree with you that the tapered stack stiffness is much more complicated than a simple factor for the varied shim diameters and thicknesses. The stackup in this case is a series of multi-order terms combined. Usually I just compare it to the LS shims, try to pick an average of the stack, and work with past experience. All this talk about valving stiffness is just a step towards quantifying the important part. This is the actual opening at a given velocity, which helps quantify the force. ---------------------- To get a visual representation of valving changes try graphing the stiffness as a slope. For example use the LS stack (6 shims @5mm overhang) as a nominal "unit" slope. Then graph the force vs. displacement of the shim stack to open. This slope extends to the point of crossover displacement. The gap is .1mm in the stock valving shown above. Then combine the HS and LS stiffness to make a new slope and continue the graph upwards. Make a guess that the HS stack here is twice as stiff. This makes the combined stiffness 3 times as much. The new slope is 3 times steeper past .1mm to .4mm (??). Now this graph and $.15 gets you a cup of coffee. This is a start on comparing the effects of differing shim configurations. More shims, thicker shims, and bigger clamping shims all stiffen and change the slope. Crossover gap shifts the transition. In the graph various shim stacks can be compared for number, thickness, clamping, and crossover shims. --------------- The stiffness is proportional to: -Number of identical shims on a given overhang -Thickness cubed -Overhang to the clamp or crossover cubed The crossover shifts the start of the HS stiffness and always to a steeper slope ----------- This is a crude approximation, but a start for your spread sheet MACE. ----------- For now I'm getting a few more shims and taking Shocknut's suggestion to try a slightly smaller .2mm crossover rather than .25mm. James (This is much like jetting, the needle taper doesn't mean as much as the position relative to the nozzle... the opening for fluid flow) ****** REVISED FOR CLARITY ****** [This message has been edited by James Dean (edited 11-14-2000).] [/QUOTE]
Verification
Which ocean is California closest to?
Post reply
Forums
MX, SX & Off-Road Discussions
Dirt Bike Mods & Maintenance
Rocky, rooty trail settings.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top
Bottom