Setting up your Bike
Introduction
All of Öhlins advanced suspension products are adapted to the brand and model. This means that length, travel spring action and damping characteristics, are tested individually just for the motorcycle that you have decided to fit with Öhlins suspension. Following instrucion can be found in the Owners Manual for Road & Track Shock Absorbers.
Before installation
Öhlins Racing AB can not be held responsible for any damage whatsoever to shock absorber or vehicle, or injury to persons, if the instructions for fitting and maintenance are not followed exactly. Similarly, the warranty will become null and void if the instructions are not adhered to.

WARNING!
1. Installing a shock absorber, that is not approved by the vehicle manufacturer, may affect the stability of your vehicle. Öhlins Racing AB cannot be held responsible for any personal injury or damage whatsoever that may occur after fitting the shock absorber. Contact an Öhlins dealer or other qualified person for advice.

2. Please study and make certain that you fully understand all the mounting instructions and the owners manuals before handling this shock absorber kit. If you have any questions regarding proper installation procedures, contact an Öhlins dealer or other qualified person.

3. The vehicle service manual must be referred to when installing the Öhlins shock absorber.

Tuning the Suspension
Motorcycle road holding qualities
All motorcycles are designed with a suspension geometry that includes height and fork angle. The changing of components can affect this and it is therefore essential that both the rear and the front ends match each other.

Changing to Öhlins suspension gives optimum performance only when both the front fork and the rear suspension interact properly. It is of great importance that the front and rear loaded heights are within the specified values.

Design
All Öhlins shock absorbers are pressurised. The fluid is put under gas pressure and the gas and the fluid are kept apart by a separating piston. The separating piston is often fitted in a separate reservoir, connected by hose, or fixed directly on top of the shock absorber (piggyback).

There are also types of shock absorbers where everything is fitted inside the main cylinder tube (internal gas reservoir), and even a small number of emulsion shock absorbers that do not have a separating piston. Pressurisation of the fluid is made with nitrogen. The pressurisation prevents cavitation of the fluid and the shock absorbing action is therefore more even. The external reservoires also contribute to better cooling of the fluid, giving longer service life for both the fluid and components.

Öhlins shock absorbers have integrated temperature compensation. As the temperature increases and the fluid flows more easily, the flow is controlled accordingly. The shock absorbing effect is therefore independent of the temperature.

The more advanced models permit individual adjustment of compression damping and rebound damping, and also certain adjustment of the length of the shock absorber.

Öhlins shock absorbers provide the possibility for adjustment, making them adaptable to most motorcycles, riders and ranges of use. All of the shock absorbers have adjustable pre-loading of the spring action; either mechanically or hydraulically.

Function
Fluid is forced through needle valves at a low rate of flow (Fig.3) and through a number of apertures in the piston (Fig.4) at a high rate of flow. The flow through these apertures is regulated by shims (thin steel washers, Fig.5) that at high pressure are deflected to open for the fluid. On most models the needle valves can be set individually.

By altering the size of the shims stack (i.e. number, thickness, diameter) the characteristics of the damping action can be varied (this should only be done by Öhlins authorized service workshops).

Compression damping
When movement of the motorcycle causes compression in the shock absorber, the fluid flows through the needle valve (combined compression and return valve) in the piston rod. If velocity of the piston is high, i.e. in the case of rapid compression, this will not be sufficient and consequently the shims underneath the piston will open to allow a greater rate of flow (Fig.6).

The fluid that is displaced by the volume of the piston rod is forced into the external fluid chamber via a separate compression valve. Even this valve is fitted with shims that open at high piston velocity. The separating piston is displaced, thus increasing the gas pressure.

Rebound damping
When the spring presses the shock absorber out again, the fluid flows back through the needle valve in the piston rod. The fluid flowing into the chamber is forced by the pressure of the gas back into the shock absorber via a separate non return valve.

If velocity of the piston is high, the shims on top of the piston will also open to allow the fluid to flow though (Fig.6).

Settings
Basic setting
Always ensure that the basic setting made by Öhlins is correct. It is adapted to the make and model (in its original state) and for a rider of average weight.

Spring pre-load
Pre-load on the spring/springs is very important because it affects the height of the motorcycle and the fork angle.

Everything must harmonize
In the recommendation table there are Öhlins front fork springs that are specifically adapted to the shock absorbers recommended for your motorcycle.

If none is noted in the table, then "intact" original springs are the right choice. Incorrect spring action can produce a fork angle that is too steep or too flat. This in turn will give a tendency for oversteering or understeering, which could seriously affect the handling characteristics of the motorcycle.