A general misconception in shim stack tuning is the high speed stack controls high speed damping. That creates the perception removing shims from the high speed stack “loosens-up” high speed damping.

Dyno testing and Shim ReStackor calculations show that approach does not work.

Ride tests of the “jake norm” stack determined the setup needed softer high speed damping to give better ground compliance.

Jake wanted to replace the stack taper with a straight stack of six shims to remove the stack taper and “loosen-up” high speed damping.

MXScandinavia ran the dyno test and the two configurations (data points) show no difference in damping. Shim ReStackor calculations show the same thing (lines).

The shim stack can be tuned to soften high speed damping and that requires a preloaded ring-shim (more).

High speed stack stiffness has little influance on high speed damping force measured on the dyno