Damping is the process of absorbing energy of impacts transmitted through the forks or rear shock on the compression and rebound stroke. A set of forks, shocks or struts are considered dampers. They slow the rate at which the suspension absorbs or releases energy. Damping is necessary to prevent uncontrolled spring oscillations in the suspension. The introduction of damping will absorb some or all of the energy imparted to the suspension by a bump. The oscillation will be reduced or eliminated, depending on the degree of damping. The up and down (kinetic) energy absorbed by the spring is restricted as oil flows through a valve in the damper body, resulting in hydraulic friction. This hydraulic friction creates heat, (thermal energy). This is why hard worked suspensions, such as in motocross, sometimes overheat. A damper is an energy absorber, matched to the rate of the spring, vehicle and rider weight, style of riding or intended type of use the machine. An underdamped bike feels loose and inprecise, without enough damping resistance the bike movement tends to pogo or hobbyhorse.
   Imagine that a large bump has fully compressed a suspension strut or shock. At that instant, energy is stored in the spring as potential energy. As the spring rebounds to its static length it gives up this energy, which without damping, would be transferred entirely to the mass of the bike in the form of kinetic energy (energy of motion). This would cause the spring, and suspension, to extend well beyond its normal position. This will have transferred the kinetic energy, in the opposite direction, back into stored energy in the spring, which will then repeat the whole process again. After any bump, we would proceed down the road as if on a pogo stick.

   Damper Speed is the relative speed in which the moving end of a damper compresses (shortens) or rebounds (extends). Typically discussed as High Speed Damping (HSD) and Low Speed Damping (LSD) which include 4 different cycles (HSC, HSR, LSC & LSR) of the shock movement.
    HSD (High Speed Damping) controls fast verticle movements of suspension components caused by road characteristics such as square-edged bumps. HSD is independent of motorcyle speed.
    • HSC (High Speed Compression) circuit in the shock absorber or suspension fork is tuned to provide suspension travel control at high speed over square-edged bumps. Too low of HSC damping will cause excessive bottoming out in rough terrain. Too high of HSC damping will minimize suspension travel in rough terrain and cause loss of traction.
    • HSR (High Speed Rebound) circuit is the opposite of HSC damping, as it effects rebound. A damper with too slow of a rebound setting will stay compressed after hitting a bump, and cannot rebound quickly enough to absorb the impact of a second or third bump. Properly set-up rebound dampening will prevent a shock from going past its starting point. "Pogoing", (when the rear shock rebounds so quickly that the rear wheel leaves the ground), will occur if the HSR is set too high.

    LSD (Low Speed Damping) controls slow verticle movements of the suspension components such as those caused by rolling bumps, wavy pavement, accelleration or in the case of fork springs, while making turns or braking, independent of motorcycle speed.
    1. LSC (Low Speed Compression) circuit is affected most when riding through turns. LSC damping is the damping circuit in the shock absorber or fork that is tuned to provide suspension travel at low damper speed conditions. Too low of LSC damping will cause the excessive travel use, brake dive, rear end wanting to come around while braking and wallowing of the bike on small bump terrain. Too high of LSC damping will cause loss of traction on small bumps.
    2. LSR (Low Speed Rebound) circuit is the opposite of LSC, as it effects rebound. If LSR is set too low the damper will bounce or chatter over bumps, if set too high the damper will pump down on small bumps, unable to return to its sag point between bumps until it uses up all of its travel forcing the chassis to take the brunt of the bump resulting in a very abrupt "tank-slapper" movement, lose tire traction and possibly crash.