Contents Design How the shocks work When you are racing External adjusters Options Technical info

How the shocks work
At low shaft speeds the damping oil is forced through an adjustable bleed valve in the main piston. The valve affects mainly rebound damping and has only a small effect on compression damping, see below.

The adjuster is connected to the valve via an aluminium shaft, which runs inside the piston shaft. When the temperature in the shock increases the aluminium shaft extends, thereby closing the bleed valve gradually.
    This diminishes the influence of the oil viscosity changes due to temperature, keeping the flow through the valve virtually the same, regardless of temperature.
    With the second adjustable bleed valve, on the top of the reservoir, you can adjust the compression damping.
    The valve restricts the flow to the reservoir but not from it, thereby only influencing the compression damping, see below.

At higher shaft speeds the damping forces are primarily controlled by the main piston and its compression- and rebound shim stacks. By changing the number, diameter, and thickness of the shims in the stack and by using different jets in the valves, your Öhlins shock absorbers are tailor-made for your car.

When you are racing

On a smooth track
When you are racing on a smooth track and the shock absorbers are compressed slowly (low shaft speed), the damping oil is forced only through the adjuster valve in the piston shaft, fig 1, flow 3.
    The oil displaced by the piston shaft is forced through the independent compression damping adjuster out into the external reservoir, fig 2, flow 3.
    The floating piston in the reservoir is forced to move, compressing the gas behind it.
    When the shock absorber extends, the pressure behind the floating piston will force the oil through a one-way valve, and back into the shock absorber body, fig 3, flow 1 and 2.
    The oil beneath the piston returns through the adjuster valve in the piston shaft, fig 4, flow 3.

Hitting a bump
When you are hitting a bump the shock absorbers are compressed fast (high shaft speed). The oil can not be forced " fast enough" through just the valve in the piston shaft. The pressure on the compression side increases and opens the shim stack covering the compression orifices in the piston, fig 1, flow 2.
    Also, oil displaced by the piston shaft can not be forced through just the valve in the reservoir. The pressure increases and a shim stack, parallel to the valve, opens, fig 2, flow 1 and 2.
    The floating piston is forced to move, compressing the gas.
When the shock absorber extends, the floating piston will force the oil through the one-way valve back into the shock absorber body, fig 3, flow 1 and 2.
    The pressure difference over the piston is still high and the flow can not be forced through just the valve in the piston shaft. The shim stack covering the rebound orifices in the piston opens and the oil returns, fig 4, flow 1.

External adjusters
The Öhlins LMJ shock absorbers have the low speed compression adjustment knob located on top of the reservoir. The low speed rebound adjuster is located, easy to reach, at the lower end of the piston shaft
    Both the adjusters have a normal right-hand thread. Click position zero (0) is when the adjusters are turned clockwise to fully closed, and then opened to the first click.

Making adjustments
Suspension settings are dependent on your car's weight, your driving style, track conditions etc. If you are not happy with our recommended settings, here are a few guidelines and ground rules how to make adjustments.
    To make improvements, it is important to understand the function of the shock absorbers and through testing learn how they affect the handling of your car.
    When making adjustments, always start with the Öhlins recommended settings. Keep notes, make adjustments one at a time... and in small steps.
    The adjusters should normally not be adjusted in steps of more than 2 clicks at a time and not outside the usable click range.
    When you think you have made an improvement, go back to what you started with and double check to be sure. Pay attention to changes in conditions like tires, temperatures, etc.
    In general, compression damping changes should be used to influence the car's stability and response, while rebound damping changes should be used to influence comfort and traction.
    When you need more damping force, you should mainly try to increase compression damping and use as little rebound damping as possible. This usually means that you gain comfort and handling performance.

Options
Double digressive piston:
This piston produces damping curves with a steep low-speed part and a flat high-speed part.

High frequency piston:
Excellent for traction and grip on flat tracks.

One way shaft jets:
Allows the compression bleed to be smaller than the rebound bleed.

Parallel compression valve:
Allows the rebound bleed to be smaller than the compression bleed and makes it possible to produce double-knee curves.

Technical information

Type	Extended Length inches	Compressed  Length Inches	Stroke Inches	Body  Length Inches	Part No.
LMJ	17.1"	11.6"	5.5"	9.75"	LMJ 55000
LMJ	19"	12"	7"	10.75"	LMJ 57000
LMJ	23.3"	14.3"	9"	12.25"	LMJ 67000