Shock absorbers or shocks were built to help absorb the up-and-down shock created by the springs whenever a vehicle hits a bump. Aside from absorbing the impact, they also keep the car or truck easily maneuverable even after a bumpy ride. The absence of shock absorbers would definitely result to a bouncing ride as energy is stored in the spring and then released to the vehicle, oftentimes exceeding the permitted range of suspension movement.
Most spring-based shock absorbers employ coil springs or leaf springs, though torsion bars can be used in torsional shocks as well. Springs alone are not shock absorbers as they only store and do not distribute or absorb energy. Modern vehicles typically use both springs or torsion bars along with hydraulic shock absorbers. With this setup, the shock absorber is reserved specifically for the hydraulic piston that takes in the vibration.
Today's technologically-advanced shock absorbers are fitted with velocity hydraulic damping devices which provide increased speed in the movement of the suspension to attain greater resistance. The result is a versatile shock absorber that can easily adopt to various road conditions. The effects of constant bounce, sway, brake dive and acceleration squat are thus significantly reduced.
Current designs of shock absorbers are either in twin tube designs and mono tube designs. A twin tube shock absorber is made up of an inner and outer tube that work seamlessly together to achieve its intended purpose while a mono tube is made up of one tube mounted in an upside down position to help reduce the load.