The ShockStop comes with 5 different elastomers to choose from so everyone can dial in the perfect feel. 

Below is our recommended chart from the instructions that provides a good starting point when first setting up the stem:

The chart below shows the full list of elastomer combinations, in order of increasing stiffness:

We provide lots of great guidance on elastomer selection and installation in our video which can be found in the "Instructions" tab on the ShockStop page of the website.