Ohlins MX, ENDURO, OFF ROAD Owner's Manual
1
Including:
Safety
Tuning the
suspension
Design
features
Function
Basic
adjustments
Fine
tuning
Inspection,
maintenance
Owners Manual
Öhlins shock absorbers, MX/ENDURO/OFF ROAD
Photo: Ray Archer
2
Safety signals
Important information concerning safety is
distinguished in this manual by the
following notations:
The Safety alert symbol means:
Caution! Your safety is involved.
WARNING!
Failure to follow warning instructions
could result in severe or fatal injury
to anyone working with, inspecting or
using the suspension, or to bystanders.
CAUTION!
Caution indicates that special precautions must be taken to avoid damage to the suspension.
NOTE!
This indicates information that is of
importance with regard to procedures.
Introduction
All of Öhlins advanced suspension products are
adepted to the brand and model. This means that
length, travel springaction and damping characteristics, are tested individually just for the
motorcycle that you have decided to fit with
Öhlins suspension.
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.
© Öhlins Racing AB.
All rights reserved.
Any reprinting or unauthorized use
without the written permission of
Öhlins Racing AB is prohibited.
Printed in Sweden.
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
NOTE
Öhlins products are subject to continual improvement and development. Consequently, although
these instructions include the most up-to-date
information available at the time of printing, there
may be minor differences between your suspension and this manual. Please consult your Öhlins
dealer if you have any questions with regard to
the contents of the manual.
Contents
Saftey signals ................................................ 2
Tuning the suspension ................................... 3
Design ........................................................... 3
Function ........................................................ 4
Compression damping ................................ 4
Rebound damping ....................................... 4
Settings ......................................................... 5
Basic settings .............................................. 5
Setting the spring preload ............................. 5
Measuring .................................................... 5
Recommendation ........................................ 5
Adjusting ...................................................... 6
Front fork spring .......................................... 6
Setting the shock absorber lenght ................. 6
Setting the damping ...................................... 7
Setting your motocycle .................................. 8
Start with rebound damping ........................ 8
Compression damping ................................ 8
Inspection and maintenance ......................... 9
3
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 the
greatest importance that the front and rear loaded
height are within the specified values.
In the mounting instruction, see section: Setting
the spring preload.
Design
Most of the Öhlins shock absorbers are of the De
Carbon type (Fig.1). 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 fluid chamber, connected
by hose (1), or fixed direct on top of the shock
absorber (piggyback) (2).
There are also cases where everything is fitted
inside the main shock absorber (internal gas
reservoir) (3).
The most advanced shock absorber has twin
pistons. This ensures position sensitive damping
in relation to the degree of compression. One of
the pistons is active throughout the entire lenght
of stroke, while the second piston begins to work
in the event of powerful compression of the shock
absorber (4)
Pressurization of the fluid is made with nitrogen.
The pressurization prevents cavitation of the fluid
and the shock absorbing action is therefore more
even. The external fluid chambers also contribute
2. Spring preloading
C-spanner
Mechanical adjustment
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.
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 preloading of the
spring action (Fig.2).
A few models have an adjustable end eye, making it possible to alter the lenght of the shock
absorber 12mm (Fig.3).
1. Design principles
12 43
1. External reservoir
with hose connection
2. External piggyback
reservoir
3. Internal gas reservoir
4. Twin piston
shock absorber
Gas
Oil
Shock absorber
piston
Oil
Gas
Separating
piston
Oil
Gas
3. Adjustment of shock
absorber length
-
+
Adjustment
nut
Twin
piston
4
Function
The function, in principle, is that fluid is forced
through needle valves at a low rate of flow (Fig.4)
and through a number of apertures in the piston
(Fig.5) at a high rate of flow. The flow through
these apertures is regulated by shims (thin steel
washers) 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 (Fig.6)
(ie, number, thickness, diameter) the characteristics of the damping action can be varied (this
shall 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, ie, 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.7).
The fluid that is displaced by the volume of the piston rod is forced into the external fluid chamber via a
separate compression valve. 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 nonreturn
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.7).
5. Piston with apertures4. Flow through
needle valve
6. Shims stack
Stop washer
Shims stack
Piston
Compression flow Rebound flow
7. Flow through piston
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