The physics of a shock absorber as it contributes to a Mass Spring Damper System is explored.

Resistive forces are produced by forcing suspension fluid through ports in a midvalve or base valve to remove energy from an oscillating vehicle.

Of note, is that as a damper rod moves into a shock body the suspension fluid in the shock body is displaced and needs somewhere to go. On the shocks we are dealing with in this video that excess damper fluid is pushed into a piggyback reservoir.

For anyone wondering about the motorcycle...
It is a 2011 KTM 250xc with a 300xc cylinder / piston. The WP forks and shock have been revalved for woods riding. All bike footage is from July in the Colorado Springs Area. Shinko M216 Front tire and Sedona rear tire.