Page 1
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
Page 2
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
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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
Page 4
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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Settings
Basic settings
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.
WARNING
Incorrect spring action can give 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.
The original setting of the shock absorber, when
delivered from Öhlins, should always be a base
when the settings are changed by use of the
adjustment devices.
Recommendations:
The difference should not deviate from the
following sizes, if no other recommended settings
are given in the Mounting instructions:
Free sag: (R1-R2), (F1-F2)
Rear: MX/Off-Road 30±5 mm
Front: MX/Off-Road 30±5 mm
Ride height: (R1-R3), (F1-F3)
Rear: MX 100±5 mm
Off Road 30% of the total stroke
Front: MX/Off-Road 80±5 mm
Setting the spring preload
1. Measuring:
Preload on the spring/springs is very important,
because it affects the height of the motorcycle and
the fork angle. Consequently, handling characteristics
can be changed, even negatively. Proceed as follows
(it will be much easier if done by two persons):
• Place the motorcycle on a stand, so the
front fork and the rear end are in fully
extended position.
• Measure the distance, eg, from the
lower edge of the rear mudguard or
from a point marked by a piece of tape,
immediately above the rear wheel axle,
to the wheel axle (R1).
• Make a similar measurement on the front axle,
e.g., from the bottom of the upper fork crown
to the front wheel axle (F1).
• Allow the motorcycle (without rider) to
apply load on the springs and repeat the
measuring procedure (R2, F2).
• Then take the same measurements with
the rider and equipment on the
motorcycle (R3, F3). It is important that the rider
has a correct riding posture, so that the
weight is balanced on the front and rear
wheel in the same way as when riding.
Bike on a stand.
F1
R1
Bike on the ground.
F2
R2
Bike with rider on.
F3
R3
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2. Adjusting
Adjust the preload with the rings on the shock
absorber.
Hold the upper ring and adjust the lower one
to the desired position (Fig.8). Then lock with the
upper ring.
NOTE!
If ride height is higher than recommended, softer
spring/springs must be used.
If ride height is lower than recommended,
harder spring/springs must be used.
Contact your Öhlins dealer for advice.
Front fork springs
To optimize the road holding qualities of a
motorcycle the front fork must match the rear
suspension. Öhlins springs are available for a
large number of motorcycles (Fig.9). These, in
combination with Öhlins shock absorbers, contribute to superior road holding qualities. The
original make of springs should be used if there
are none of our springs in the recommendation
table. However, they must be in good condition
and not fatigued. Remember to change the fluid
in the front fork at least once every year. We
recommend Öhlins front fork oil.
WARNING!
It is important that the recommendation table is followed for new front springs. If there are no
recommended front springs you must ensure that
the existing springs are in good condition.
Neglecting to check the front springs could seriously
affect the handling qualities of the motorcycle
8. Spring preloading
Setting the shock absorber length
Sensitivity of the steering can be adjusted by altering the length of the shock absorber, without affecting other characteristics. The length is adjusted using two nuts down and the treaded clevis at the end
of the piston rod.
The shock absorber can be adjusted up to 12 mm.
The length may never be altered more than to where
the groove that is cut in the thread becomes just
visible (Fig.10).
Mechanical
preloading adjustment
9. Front spring kit 10. Adjustable end eye
WARNING!
If the shock absorber has an adjustable end eye/bracket, this
must not be treaded out more
than that one groove is fully visible beneath the lock nut. Make
sure that the lock nut is tightened
after adjustment.
Groove
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7
+
-
12. Adjustment of compression damping
Rebound damping action affects the characteristics
of the motorcycle most. The setting knob is located
at the bottom on the piston rod (Fig.11).
It can be adjusted in about 40 steps. The
compression damping adjuster is located at the end
of the reservoir (Fig.12). This can be adjusted in
about 25 steps.
Compression damping is set with a knob or a
screw on top of the extrernal reservoir. This can be
adjustable in about 25 steps.
Some models (PRX and PRXQ) have separate
adjusters for high speed compression and low
speed compression (Fig.13). The low speed
compression is adjusted in 25 steps.
The high speed adjuster has a wide range within
four (4) turns. Adjust a half turn (180°) at a time.
Setting the damping
The adjusting possibilities of Öhlins shock
absorbers facilitate fine setting. You can optimize
adjustments to suit your own weight and
equipment, your individual way of riding and the
condition of the road. To be able to improve the
road holding qualities it is of the utmost importance
that you fully understand the functioning of the
shock absorbers. Then you can learn by trial and
error how they affect the motorcycle.
Depending on the model there are adjustments
for rebound damping, compression damping and
adjustment of the length of the shock absorber.
Damping is set with knobs and screws with a normal
right-hand thread. By turning you can increase the
damping action or reduce it. The adjuster have
definite positions with a noticeable “click”, so it is
easy to count to the right setting.
NOTE!
When making new adjustments it is easiest to go
back to fully closed, and then count forward to
the new setting. The adjusting device should not
be turned in too hard.
On MX/Enduro dampers the adjustment must
be made when the shock absorber is cold.
NOTE!
If no ”click” is felt, on the rebound adjusting knob,
the shock absorber must be inspected by an authorized service workshop. It could be due to incorrect or lack of gas pressure.
11. Adjustment of rebound damping
= more damping
= less damping
+
+
-
-
+
-
High speed
Low speed
13. High and low speed compression damping adjusters
+
-
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Setting your motorcycle
NOTE!
Always begin with the basic settings recommended
by Öhlins. Always make notes, adjust in small steps
and make only one adjustment at a time.
Adjustments should be made with two steps (clicks)
at a time. Adjustments should not be more than
four steps from the basic setting.
By utilizing the adjustment possibilities you can
test by trial and error, and learn how they affect
your motorcycle.
Always begin by test riding the motorcycle with
all adjustments at their basic setting. Choose a
short run of varying character, ie, long and sharp
bends, hard and soft bumps. Keep to the same
run and adjust only one setting at a time.
Turn 1/2 turn at a time. Test run and make any
necessary correction.
When you have sufficient feel of the motorcycle
then you can make further fine adjustments. It is
feeling and experience that counts.
NOTE!
Ensure that the springs are properly preloaded
before attempting to make any adjustments. A
simple rule is that increased preload of the spring
should be followed by an increase of rebound
damping by two steps.
When you feel that you have achieved an
improvement, go back to where you started and
check once more. Be observant of other relevant
factors such as tyres, temperature, etc. Test run
to make sure whether further fine adjustment
should be made.
Start with the rebound damping (Fig.14)
If the motorcycle feels unstable, loose and rather
bouncy then the rebound damping should be
increased. Begin by turning the adjusting knob 2
steps (clicks). Test run again and adjust one steps
back if it felt too hard and bumpy.
If the motorcycle is hard and bumpy, especially
over a series of bumps, then the rebound
damping should be reduced. Turn 2 steps, test
run and make any necessary correction. For original rebound setting see mounting instructions.
Compression damping (Fig.15)
If the motorcycle feels soft, has low riding position
and a tendency to bottom easily in long dips then
the compression damping should be increased.
Turn clockwise 4 steps and test run again.
If this was too much then turn back two steps.
Normall changes are made of high speed compression adjuster only.
If the motorcycle feels harsh and has hard
resilience, eg, over changes in the road paving,
then the compression damping must be reduced.
14. Rebound damping
Reduce
• Unstable
• Loose
• Bouncy
• Hard
• Bumpy
Increase ReduceIncrease
15. Compression damping
• Soft
• Low
• Bottom
• Harsh
• Hard
Page 9
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NOTE!
Regular maintenance and inspection contribute
to the prevention of functional disturbances.
Recommended service intervals:
MX & Enduro Approximately
20 hours of operation
Off Road 2 - 3 times a year
WARNING!
Never alter the gas pressure. Special-purpose
charging equipment and access to nitrogen is
required. The gas pressure should normally never
be altered.
Inspection and maintenance
Clean the shock absorbers externally with a soft
detergent . Use compressed air . Be careful that
all dirt and debris is removed.
Lift the bump rubber and clean the area below
(Fig.16).
Keep the shock absorbers clean and always spray
them with oil (QS 14, WR40 or CRC 5-56) after
washing the motorcycle.
Inspection points (Fig.17):
1. Check ball joints for possible excessive play.
2. Check the piston shaft for leakage and damage.
3. Check the shock absorber body and for
external damages.
4. Check the external reservoir for damages that
can restrict the floating piston from moving freely.
5. Excessive wear of rubber components
6. Fastening to the vehicle
• Check the hose equipped models for leaks in
hose and inlet plugs.
Preventive maintenance and regular inspection
reduces the risk of functional disturbance. If there
is any need for additional service, please get in
touch with an authorized Öhlins service workshop.
There they have the necessary tools and knowhow for whatever you need.
NOTE!
Make certain that your shock absorbers are
always filled with Öhlins High Performance Shock
Absorber Oil.
1
1
3 4
3
2
5
5
6
16. Lift the bump rubber and
clean the area below.
17. Inspection points:
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General handling set-up
Front suspension.
Front fork travel is not used to its full
capacity. Harsh feeling, front wheel grip is
not satisfactory in bumpy turns.
Suspension too hard.
• Decrease the front fork
compression damping.
• Change to softer springs.
Suspension bottoming, too soft during
entire travel.
Spring too weak or compression damping too soft.
• Increase oil level 5 mm.
• Increase compression damping.
• Change to stiffer springs.
Suspension bottoming, but can handle
smaller bumps.
Damping force not progressive enough.
• Increase the oil level.
Can handle smaller bumps but is too hard
during the last part of the travel.
Damping force is too progressive.
• Decrease the oil level.
Front end feels low, initially feels soft, but is
not bottoming.
The initial spring rate is too soft or spring preload
is too low.
• Increase the spring preload.
Feels harsh over small bumps, but using full
wheel travel.
Too much spring preload or too much compression damping.
• Increase the oil level or change
to softer springs.
• Decrease the compression
damping.
• Decrease the spring preload.
• Clean the oil seals and scrapers.
Use Öhlins grease 148-01 for
regreasing.
Can handle the first in a series of bumps but
feels hard after a few more bumps. Frontal
grip insufficient in rough and bumpy turns.
Too much rebound damping.
• Decrease the rebound damping.
Front end rebound too fast after a bump.
Front wheel grip insufficient in bumpy
curves.
Not enough rebound damping, or too much
spring preload
• Increase the rebound damping.
• Decrease the spring preload.
Front end ”ploughs”, understeers.
Shallow front fork angle. Front end too high in
comparison to rear end.
• Decrease the front fork
compression damping.
• Raise the fork legs approximately
5 mm in the triple clamp.
• Change to softer fork springs.
Front end unstable at high speed, unstable
when accelerating out of curves.
Front fork angle too steep. Front end too low in
comparison to rear end.
• Lower the fork legs approximately
5 mm in triple clamp.
• Change the front fork springs to
harder ones.
Front end unstable during deceleration.
Front fork angle too steep during braking. Front
end too low or rear end too high.
• Increase the oil level in the front fork.
• Change to harder fork springs.
• Increase the front fork
compression damping.
Front end falls into the curves (oversteering) especially in sand.
Steep front fork angle. Front end too low in comparison to rear end.
• Increase the front fork
compression damping.
• Change to harder springs.
• Lower fork leg approximately
5 mm in the triple clamp.
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Rear suspension.
Rear suspension stroke is not used to its
capacity. Suspension feels harsh. Traction
not satisfactory in bumpy curves.
Suspension hard in general or too much compression damping, too much spring pre-load.
• Decrease the compression
damping.
• Decrease the spring preload.
• Change to softer spring.
Suspension is bottoming, feels soft during
the entire wheel travel.
Spring too soft, compression damping too low.
• Increase the compression
damping.
• Change to harder spring.
Suspension is bottoming, feels harsh and sags
down too much with the rider in the saddle.
Spring too soft or compression damping too low.
• Increase the spring preload,
check ride height. 95 +- 5 mm.
• Change to harder spring if the
load is more than 100 mm.
• Increase compression damping.
Rear wheel jumps over small bumps during
deceleration or when going downhill. Traction
not satisfactory in washboard curves.
Too much spring preload, as the spring is probably
too soft, will cause the spring to extend too fast.
• Change to a harder spring in
order to achieve a balanced
position using less spring preload.
• Check the static sag and
ride height.
Rear end kicks up over bumps with sharp
edges, but can handle bumps with round
edges.
Compression damping too hard.
• Decrease the compression
damping.
Rear end becomes too low in series of
bumps. Traction not satisfactory in washboard type curves or when decelerating on
washboard ground.
Rebound damping too slow.
• Decrease the rebound damping.
Rear end very unstable. Shock does not
respond to adjustments.
Shock damping is gone, caused of low gas pressure, bad oil is used, or components are broken
in the shock absorber. Service is needed.
• Gas filling required.
• Change shock oil.
• Repair or change the shock
absorber.
NOTE!
Recommended measures are not listed in order
of importance.
One of the listed measures can be sufficient to
solve a particular handling problem.
Page 12
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07251-02, Issued 02 02 20. 500 ex.
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Öhlins Racing AB, Box 722, S-194 27 Upplands Väsby, Sweden
Phone +46 8 590 025 00, Fax +46 8 590 025 80
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