Holid Oil shock absorbers or with gas

Oil shock absorbers reduce excessive movement of the vehicle through the controlled movement of the oil under pressure. The oil  provides resistance to motion and control valves the amount of resistance. Before the development of gas charged shock absorbers, the adjustable hydraulic shock absorber holes in the valve could not be enlarged to increase driving comfort without losing the effectiveness of damping. Thus valves were limited to one of two directions: hard or soft valves. With soft valves, oil flows more easily. The result is a smooth ride, but with poor management - and a lot of sweeps and rebounds - When the valves are tough, oil flows less easily. The handling is improved, but the trip can be rough.In the past, design engineers had to choose between soft and hard valves . And either comfort or control were seen significantly lower living. Additionally, the oil buffer within the shock absorber may be mixed with air, is foamed. The engineers called this aeration. Because the foam is compressed, the amount of resistance provided by the liquid was hard to predict.