Editing Shock absorber (section)

=== Vehicle suspension ===
{{main|Suspension (vehicle)}}
In a vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improved [[ride quality]] and [[automobile handling|vehicle handling]]. While shock absorbers serve the purpose of limiting excessive suspension movement, their intended main purpose is to damp spring oscillations. Shock absorbers use valving of oil and gasses to absorb excess energy from the springs. Spring rates are chosen by the manufacturer based on the weight of the vehicle, loaded and unloaded. Some people use shocks to modify spring rates but this is not the correct use. Along with [[hysteresis]] in the tire itself, they damp the energy stored in the motion of the [[unsprung weight]] up and down. Effective wheel bounce damping may require tuning shocks to an optimal resistance.

[[Spring (device)|Spring]]-based shock absorbers commonly use [[coil spring]]s or [[leaf spring]]s, though [[torsion spring|torsion bar]]s are used in [[torsion bar suspension|torsional]] shocks as well. Ideal springs alone, however, are not shock absorbers, as springs only store and do not dissipate or absorb energy. Vehicles typically employ both hydraulic shock absorbers and springs or [[Torsion spring|torsion]] bars. In this combination, "shock absorber" refers specifically to the hydraulic piston that absorbs and dissipates vibration. Now, composite suspension systems are used mainly in 2 wheelers and also leaf springs are made up of composite material in 4 wheelers.