NITRO SHOCK ABSORBERS

CONTENTS

NEED FOR SHOCK ABSORBERS WHY GAS FILLED SHOCK

ABSORBERS? TYPES & ADVANTAGES MOUNTING TIPS

NEED FOR SHOCK ABSORBERS Springs alone cannot provide a

satisfactorily smooth ride. Oscillation of spring causes the wheel to

rebound, or bounce up and down. Control over the vehicle can be lost. Shock absorbers prevent these spring

oscillations.

HOW IT WORKS?

All shock absorbers use hydraulic fluid to convert the energy of the spring to heat.

Consists of two strokes

1. Compression &

2. Rebound

INSIDE OF A SHOCK ABSORBER

WHY GAS FILLED SHOCKS?

Rapid movement of the fluid between the chambers cause foaming.

Results in a lag because the piston moves through an air pocket which offers resistance.

Foaming results in a decrease of damping and a loss of spring control.

Pressure increases in front of the piston and drops behind it.

All together results in foaming and loss of shock absorber control.

GAS FILLED SHOCKS

Designed to reduce foaming of the oil. Construction is similar except the double

tube, here a dividing piston is used. Two chambers – oil & gas.

COMPONENTS

Upper and lower mounts. Hydraulic chamber containing hydraulic

fluid. Gas chamber containing nitrogen at

25 bars. Dividing piston.

How it works?

The piston rod is moved into the shock

absorber which displaces the oil. This causes the dividing piston to press on

the gas chamber, reducing it in size. While returning the gas pressure returns the

dividing piston to its initial position.

The pressure decrease behind the working piston cannot be high for the gas to exit from the oil column.

Thus the gas filled shock absorber operates without foaming.

TYPES AND DETAILS

There are two types of gas filled shock absorbers-

1. Mono tube with high pressure

2. Twin tube with low pressure

INSIDE OF A MONO TUBE

MONO TUBE

COMPONENTS:

1. Cylinder also called housing.

2. Piston connected to a piston rod.

3. Floating piston also called separating piston.

4. Piston rod guide.

5. Upper and lower attachment.

WORKING

The cylinder is not completely filled with

oil; the lower part contains nitrogen at

25-30 bar. Gas and oil are separated by floating

piston.

BUMP STROKE

When the piston rod is pushed in the

floating piston is also forced down slightly

increasing pressure in both section. Also the oil below the piston is forced to

flow through the piston, this generates

the bump damping.

REBOUND STROKE

When the piston rod is pulled out, the oil between piston and guide is forced to flow through the piston.

This resistance generates rebound damping. At the same time part of piston rod will

emerge from cylinder and free piston move upwards.

INSIDE OF A TWIN TUBE

TWIN TUBE

COMPONENTS:

1. Outer tube also called reservoir tube.

2. Inner tube also called cylinder.

3. Piston connected to a piston rod.

4. Bottom valve also called foot valve.

5. Piston rod guide.

6. Upper and lower attachment.

BUMP STROKE

When the piston is pushed in, oil flows to

the enlarged volume above the piston. Simultaneously a quantity of oil is also

forced to the reservoir tube.

REBOUND STROKE

When the piston is pulled out, the oil

above the piston is pressurized and flow

through the piston. Some oil flows back from the reservoir

tube to the lower part.

ADVANTAGES

Instantaneous response. Better fade resistance. Better durability. No need for re-adjustment.

TIPS BEFORE MOUNTING

Avoid stiff suspensions. Avoid new shocks to compensate for

old and tired springs. Worn shocks reduce safety and

handling. The best advice come from a mechanic

who knows your vehicle.

Thank You