GP Series

A-KIT for KTM

Front Fork & Rear Cushion

Owner’s Manual
Read this manual carefully before operating this A-KIT.
No. T634000-OME1

Introduction
Thank you very much for purchasing SHOWA A-KIT Front Fork and Rear Cushion.
A-KIT is the suspension kit that has the best performance and durability exclusively for racing. The
know-how gained at the AMA Supercross Championship, the world’s best motocross world championship, and the Dakar Rally is utilized.
Installation of the A-KIT, handling, and tuning are described in this Owner’s Manual.
Please read this manual carefully, and follow the described instructions.
Please note that installation, handling, and tuning must be conducted in a dealership or installation shopwhere there are technicians with special knowledge and skills. Make sure to change the spring, dustseal, and oil seal at a dealership or store specializing in installation.
This product is dedicated for race, so it is not covered by warranty. It is not covered by warranty if it isused outside of a race or on a vehicle outside a race circuit. Please use safely by complying with thismanual or other manual attached to motorcycle. Please contact a dealer for details.

Handling this product properly
In this manual, items that need you to comply to prevent injuries on the user and other people andproperty damage, in addition to the correct installation are shown with the following “Symbols”. Please
understand what each “Symbol” means, and read this manual.
It is the safety warning symbol. This symbol is used to call your attention
when there is a danger for personal injury. Comply with the safety items specified after this symbol to prevent injury and accident that may cause death.
WARNING

The symbol represents a content that if mishandled, “it may cause death orserious injury”.

CAUTION

The symbol represents a content that if mishandled, “it may cause injury orproperty damage”.

Note

It describes points to pay attention, and focus when conducting service.

Explanation of Icons Used in this Manual
In this manual, the following icons are displayed in illustrations for inspection and disassembling service
to proceed smoothly.
Icon

Explanation
Specify the tightening torque.
It shows the press fitting part. Press fit using an adequate adapter.
It shows a part to clamp. To prevent deformation of a part, always clamp on the specified part.
A location to apply Liquid O-Ring #400.
Replace with a new part.

Safety Caution
Caution When Installing

WARNING

Special knowledge is required to replace Front Fork and Rear Cushion.
If someone without special knowledge performed installation, and the installation was improper, it may cause damage on the motorcycle and accident.
Please make sure that replacement is conducted in a dealership or installation
shop where there are technicians with special knowledge and skills.
If the product is installed on a modified motorcycle, it may cause function andperformance deterioration.
Install this product only on a motorcycle with genuine parts of its manufacturer.

This product is a precision machine part.
Deformation and dent from a drop, hammer, and shock may cause function
and performance deterioration.
When handling and installing the product, do not drop, hammer, and apply shock.
CAUTION

If only one person handles the product, there may be a case that a motorcycle
and parts cannot be held by himself/herself.
Make sure 2 or more people work when removing and installing the product.
When installing to a motorcycle, comply with the items described in the Service Manual provided by the motorcycle’s manufacturer.

Caution when Using

WARNINGCAUTION

High-pressure nitrogen gas is filled in this product.
When disassembling and refilling nitrogen gas, the product may burst causing serious injury.
If exposed to flames and you puncture a hole, this product may burst causing
serious injury.
Replacement and discarding must be done by a specified dealership or installation shop.

There are recommended inspection items for this product to maintain its performance.
If not inspected and defects are ignored, it may cause function and performance deterioration.
When using, make sure to perform the inspection items described in this manual.
Always use the oils specified by SHOWA.
When unspecified oils are used, it may cause function and performance deterioration.

Contents
Overview of Front Fork................ 1● Inserting the slide pipe COMP into
the outer tube.............................. 15

List of Specification................................. 2

Troubleshooting of
Front Fork................................... 17

Product Features.................................... 1
Recommended Inspection Items............ 2

Tuning Method........................................ 2● Adjusting atmospheric pressure.... 2● Adjusting the compression............ 3

Overview of Rear Cushion......... 18
Product Features.................................. 18

List of Specification............................... 19● Adjusting the rebound................... 4

Recommended Inspection Items.......... 19

Available Option Parts............................ 4

Tuning Method...................................... 19

Installation Method of Front Fork
(Replacement from Standard
Specification)................................ 5● Adjusting the high speed sidecompression................................ 19

Measuring Vehicle Height Before
Replacement........................................... 5
Installation............................................... 5
Measuring Vehicle Height After
Replacement........................................... 6

Replacement Method of Springon Front Fork................................ 7
Removal.................................................. 7● Removing the cushion
S/COMP........................................ 7● Adjusting the low speed sidecompression................................ 20● Adjusting the rebound damping
force............................................ 20● Adjusting the spring installation
length.......................................... 21
Available Option Parts.......................... 21

Installation of Rear Cushion(Replacement from Standard
Specification).............................. 22

Measuring Vehicle Height Before
Replacement......................................... 22● Discharging operation fork oil
inside the outer tube...................... 7

Installation............................................. 22● Removing the spring..................... 8

Measuring Vehicle Height After
Replacement......................................... 22

Installation............................................. 10● Assembling the spring................. 10● Attaching the center bolt COMP.. 10

Replacement Method of Dust
Seal and Oil Seal........................ 14

Removal................................................ 14● Removing the dust seal andstopper ring................................. 14● Removing the slide pipe.............. 14

Installation............................................. 15● Assembling the slide pipe
COMP......................................... 15

Replacement Method of Springon Rear Cushion......................... 23

Removal................................................ 23● Removing the spring................... 23

Installation............................................. 23● Attaching the spring..................... 23

Troubleshooting of Rear
Cushion....................................... 25

Overview of Front Fork
Product Features
The A-KIT front fork for KTM vehicles feedbacks the suspension technology verified in AMA and MXGP.
“Dimplush”, the cutting-edge technology, is applied to the outer tube to improve performance. Also,“Emerald Coating” is applied to the slide pipe to improve performance and design. Furthermore, titanium
bolts are adopted for axle bolts to reduce weight.

Slide pipe
<Improved performance/design>
Emerald coating

Outer tube
<Improved performance>
Micro dimple process

Axle bolt<Light weight>
Titanium bolt

1Overview of Front Fork
List of Specification
SpringRate (N/mm)

4.8Operation oil

Type of oil

A15-00Oil amount inside damper

243 ccOil amount for outer tube
Damping force

320 ccCompression

Max -20 clicks

Rebound

Max -20 clicks

Recommended Inspection Items
BeforeridingSemi-annually

Annually

Check appearance abnormality, fallen bolts, cracks, anddistortion







Operation check of front fork







Oil leakage of front fork







Tuning Method● Adjusting atmospheric pressure

1. Set the inner pressure of the right and left
front forks to atmospheric pressure while
placing the vehicle in a vertical position andfloating the front tire.
2. Completely loosen the plug bolt .
3. Attach the plug bolt, and tighten with thespecified torque.
Tightening torque: 1.3 Nm

2

Overview of Front Fork
● Adjusting the compression
1. Turn the compression adjuster  clockwise

until it stops (the strongest position).
2. Turn one click at a time counterclockwise.
The standard position is 20 clicks.
3. Turn clockwise from the standard position
to make stronger, and counterclockwise to
make weaker.
CAUTION

Do not turn further fromthe strongest position andweakest position. It cancause damage of front fork.

[Note]
 Adjust so that right and left are on thesame position.
 Always start adjusting from the strongest
position.
 32 clicks (8 clicks/rotation) or more canbe adjusted from the weakest position to
the strongest position.
 Make sure to stop the compression adjuster on the click position.

3

Overview of Front Fork
● Adjusting the rebound1. Turn the rebound adjuster  of the cen-ter bolt COMP clockwise until it stops (thestrongest position).
2. Turn one click at a time counterclockwise.
The standard position is 20 clicks.
3. Turn clockwise from the standard position
to make stronger, and counterclockwise to
make weaker.
CAUTION

Do not turn further fromthe strongest position andweakest position. It cancause damage of front fork.

[Note]
 Adjust so that right and left are on thesame position.
 Always start adjusting from the strongest
position.
 32 clicks (8 clicks/rotation) or more canbe adjusted from the weakest position to
the strongest position.
 Make sure to stop the rebound adjusteron the click position.

Available Option Parts
To widen the vehicle height tuning and setting change, a spring for replacement is available as the optional part. For purchasing, contact the specified dealership.
Rate (N/mm)

Specification

5.0

Hard

4.8

Standard

4.6

Soft

4

Installation Method of Front Fork (Replacement from Standard Specification)
WARNING

Please make sure that installation is conducted in a dealership or installation
shop where there are technicians with special knowledge and skills.

When replacing the front fork, conduct tuning of the motorcycle posture with the following ways.

Measuring Vehicle Height Before Replacement
1. While placing a motorcycle on the ground, measure the distance from the axle shaft of the front
wheel to the top bridge, and record the value.
2. Measure above while a rider is on the motorcycle, and record the value.
3. Measure above by jacking up the motorcycle and the front wheel is dropped completely, and record
the value.

Installation
1. Remove the front fork of the vehicle.
[Note]For the removing method of the front fork,
refer to the service manual of the vehicle
manufacturer.
2. Attach the A-KIT front fork to the vehicle.
 Attach by matching the groove  of
A-KIT front fork to the upper end  ofthe upper triple clamp.
3. Tighten the screw  on the right and left
upper triple clamp with the specified torque.
Tightening torque: 17 Nm
4. Tighten the screw  on the right and left
lower triple clamp with the specified torque.
Tightening torque: 12 Nm

5

Installation Method of Front Fork (Replacement from Standard Specification)
5. Attach the fork cover on the right and left.
[Note]For the installation method of the fork cover, refer to the service manual of the vehicle
manufacturer.

6. Attach the front wheel , brake caliper ,and brake hose .
[Note]For the installation method of the front
wheel, brake caliper, and brake hose, referto the service manual of the vehicle manufacturer.
7. Tighten the screw  of the axle holder withthe specified torque.
Tightening torque: 20 Nm

Measuring Vehicle Height After Replacement
WARNING

After replacement, the caster angle of the front fork is changed from the
pre-replacement state. If ridden in this condition, it is very dangerous because
the motorcycle behavior may be unstable and the brake performance may
change. Before riding, make sure to tune the motorcycle posture.

CAUTION

When setting problems are not solved, contact your nearest dealership that
handles SHOWA products.

6Replacement Method of Spring on Front Fork
Removal● Removing the cushion S/COMP

1. Record the current position of the compression adjuster  and rebound adjuster .
2. Turn the compression adjuster and reboundadjuster counterclockwise, and set to theweakest position.
3. Before disassembling the front fork, clean
the fork (especially the slide pipe sliding
part and center bolt peripheral area).

200 mm

4. Clamp the outer tube  on thepart,
and remove the cushion S/COMP  using
the special tool.

90 mm[Note]
Special tool: Lock nut wrench, 50 mm● Discharging operation fork oil inside the outer tube

1. Lower the outer tube slowly until the dust
seal of the outer tube  touches the axle
holder .
2. Slowly extend and retract the outer tube for several times to discharge the oil inside
the outer tube.

7Replacement Method of Spring on Front Fork
3. Remove the O-ring  from the cushion S/
COMP.

● Removing the spring

1. Protect the axle holder part with the waste
cloth, and fix with a vice.
2. Loosen the center bolt .

200 mm

3. Clamp the outer tube  on thepart,
and attach the cushion S/COMP  temporarily using the special tool.

90 mm[Note]
Special tool: Lock nut wrench, 50 mm

4. Push the outer tube, and push out the center bolt  from the axle holder .
5. Maintain in the condition that the outer tube
is pushed, and attach the stopper plate 
between the axle holder and lock nut .
6. Loosen the lock nut, and remove the centerbolt COMP.

8

Replacement Method of Spring on Front Fork
55 mm (2.2 in)[Note]
See the figure, and make a 2.0 mm thick
stopper plate.

39 mm (1.5 in)

25 mm (1.0 in)

15 mm (0.6 in)
R 7.5 mm (0.3 in)

7. Remove the push rod  from the piston rod
COMP . Maintain in the position that theouter tube is pushed, and remove the stopper plate .
Remove the front fork ASSY from the vice.

CAUTION

When removing the stopper plate, the cushion S/
COMP pops out by the
spring’s reaction force.
While holding the cushion
S/COMP to the directionof the axle holder, remove
the stopper plate.

90 mm

200 mm

8. Clamp the outer tube  on thepart,
and remove the cushion S/COMP  using
the special tool.

9. Remove the spring from the front fork
ASSY.

9

Replacement Method of Spring on Front ForkInstallation● Assembling the spring

1. Check the seat of the lock nut  at the endof the piston rod of damper COMP.
[Note]
Wipe off the oil attached on the damper
COMP.

2. Remove the operation fork oil attached on
the spring  and damper COMP .
3. Attach the spring on the damper COMP,
and insert to the front fork ASSY .

4. Using the special tool, temporarily tighten
the cushion S/COMP  to the outer tube
.
[Note]
Special tool: Lock nut wrench, 50 mm 

● Attaching the center bolt COMP

1. Protect the axle holder with the waste cloth,and fix with a vice.
2. Push the outer tube, and push out the locknut  from the axle holder .
3. Maintain in the condition that the outer tube
is pushed, and fix between the axle holder
and lock nut with the stopper plate  madeduring disassembly.

10Replacement Method of Spring on Front Fork
4. Insert the center bolt COMP  to the pushrod  by matching to the D shape of thepush rod.
[Note]
Match with the cross section D shape of thepush rod.

5. Apply grease on a new O-ring , and attach on the center bolt .
6. While matching the center bolt with the D
shape of the push rod, tighten and insert tothe end as shown in .
[Note]
Tighten and insert the rod pipe to the end of
the center bolt .
7. Tighten the lock nut  with your hand until
it touches the center bolt .
8. Hold the lock nut, and tighten the center boltwith the specified torque.
Tightening torque: 28 Nm

9. Maintain in the condition that the outer tube
is pushed, remove the stopper plate.
10. Tighten the center bolt to the axle holder
with the specified torque.
Tightening torque: 69 Nm

11Replacement Method of Spring on Front Fork
11. Remove the front fork ASSY from the vice.
12. Measure the distance between the axle
holder part and outer tube, and check it iswithin the standard value.

317mm[Note]
Standard: 317 mm

13. Using the special tool, remove the cushion
S/COMP  from the outer tube .
[Note]
Special tool: Lock nut wrench, 50 mm 

14. Pour operation fork oil into inside of the fork
tube.
[Note]
Operation fork oil: A15-00
Standard oil amount: 320 cm3

15. Apply grease on a new O-ring , and attach to the groove part  of the damper
COMP .

12

Replacement Method of Spring on Front Fork

200 mm

16. Slowly pull up the outer tube , fix theclamp part, insert the damper COMP into the outer tube and tighten with thespecified torque using the special tool.

90 mm

Tightening torque: 76 Nm[Note]
Special tool: Lock nut wrench, 50 mm 13

Replacement Method of Dust Seal and Oil Seal
RemovalFor removing procedures, see “● Removing the cushion S/COMP” (Page 7), “● Discharging operation fork oil inside the outer tube” (Page 7), and “● Removing the spring” (Page 8).

● Removing the dust seal and stopper ring
1. Remove the dust seal  and stopper ring from the outer tube .

● Removing the slide pipe

1. Repeat the action to apply the slide pipe 
several times, and remove the slide pipe
from the outer tube .

2. While opening the split surface of the slide
bush  with a flathead screwdriver, remove the slide bush.
3. Remove the guide bush , the backup ring, the oil seal , the stopper ring , thedust seal .

14

Replacement Method of Dust Seal and Oil Seal
Installation● Assembling the slide pipe COMP

1. To protect the lip part of the seal, attach thejig  on the slide pipe.
2. Apply grease to the lip part of a new dust
seal  and oil seal .
3. Attach the dust seal , stopper ring ,and oil seal  on the slide pipe .
[Note]
Face the mark surface to the dust seal side,
and attach the oil seal to the slide pipe.

4. Remove the jig , and attach the seal
spacer , guide bush , and slide bush.

● Inserting the slide pipe COMP into the outer tube
1. Insert the slide pipe COMP  into the outertube .

15

Replacement Method of Dust Seal and Oil Seal
2. Using a fork seal screwdriver (a commercial
product) , drive the guide bush  and oilseal  into the outer tube  in the order.
3. Drive in the oil seal  to the position thatthe stopper ring groove is visible.
4. Attach the stopper ring  firmly to the stopper ring groove  of the outer tube.
5. Using a fork seal screwdriver (a commercial
product), press fit the dust seal  to theouter tube.

16Troubleshooting of Front Fork
Symptom

Cause

The suspension operation is
soft.

Inadequate damping force tuning.

Tune suspension.

Viscosity of operation fork oil
is low

Replace oil (SHOWA genuineoil).

The amount of operation fork
oil is low

Adjust the oil amount.

The suspension operation is
hard.

Noise in the front fork.

Measures

Settling of the spring.

Replace spring.

Bent slide pipe.

Stop using immediately, andcheck at the dealership or installation shop.

Viscosity of the operation fork
oil is highReplace oil (SHOWA genuineoil).

The amount of operation fork
oil is high

Adjust the oil amount.

Damage.

Stop using immediately, andcheck at the dealership or installation shop.

17

Overview of Rear Cushion
Product Features
The A-KIT rear cushion for KTM vehicles feedbacks the suspension technology verified in AMA and
MXGP as well as the front fork.
By using the aluminum 3-piece type for the damper case, it reduces its weight. In addition, SPG ADJ is
made of resin to reduce weight and improve design. Furthermore, “Emerald Coating” is applied to therod to improve performance and design.

Damper case
<Light weight>
Aluminum 3-piece type

SPG ADJ<Light weight/improved design>
Use of resin

Rod<Improved performance/design>
Emerald coating

18

Overview of Rear Cushion
List of Specification
SpringRate (N/mm)

46

Operation oil

Type of oil

SS25

Damper oil amount392 cc900

Gas filling pressurekPa

Rod sizeφDamping force

Low speed compression

Max -20 clicks

High speed compression

Max -2-5/6 clicks

Rebound

Max -20 clicks

18

Recommended Inspection Items
BeforeridingSemi-annually

Annually

Check appearance abnormality, fallen bolts, cracks, anddistortion







Operation check of rear cushion







Oil leakage of rear cushion







Tuning Method● Adjusting the high speed side compression
1. Turn the adjuster  clockwise until it stops(the strongest position).
2. Place the standard position. Turn the adjuster -2 turns and -5/6 turns counterclockwise from the strongest position.

CAUTION

1/6

Do not turn further fromthe strongest position
and weakest position. It
can cause damage of rearcushion.

[Note]
 Turn clockwise to make stronger, andcounterclockwise to make weaker.
 Perform adjustment 1/6 turns at a time.
 Always start adjusting from the strongest
position.

19

Overview of Rear Cushion● Adjusting the low speed side compression
1. Turn the adjuster  clockwise until it stops(the strongest position).
2. Place the standard position. Turn counterclockwise from the strongest position.
Match with 20 clicks.

CAUTION

Do not turn further fromthe strongest position
and weakest position. It
can cause damage of rearcushion.

[Note]
 Turn clockwise to make stronger, andcounterclockwise to make weaker.
 Always start adjusting from the strongest
position.
 30 clicks (8 clicks/rotation) or more canbe adjusted from the weakest position to
the strongest position.
 Make sure to stop the adjuster on the click
position.

● Adjusting the rebound damping force
1. Turn the adjuster  clockwise until it stops(the strongest position).
2. Place the standard position. Turn counterclockwise from the strongest position.
The standard position is 20 clicks from thestrongest position.

CAUTION

Do not turn further fromthe strongest position
and weakest position. It
can cause damage of rearcushion.

20

Overview of Rear Cushion[Note]
 Turn clockwise to make stronger, andcounterclockwise to make weaker.
 Always start adjusting from the strongest
position.
 30 clicks (8 clicks/rotation) or more canbe adjusted from the weakest position to
the strongest position.
 Make sure to stop the adjuster on the click
position.

● Adjusting the spring installation length
1. Loosen the bolt  of the band with a hex-

agonal wrench (4 mm).
2. Turn SPG ADJ , and adjust the spring
installation length.
[Note]
 Spring installation length standard: 243mm
 For a standard spring, the spring installation length changes 2.0 mm with one
rotation of SPG ADJ.

3. After adjusting, tighten the bolt  with thespecified torque.
Tightening torque: 5 Nm

Available Option Parts
To widen the vehicle height tuning and setting change, springs for replacement are available as theoptional part. For purchasing, contact the specified dealership or installation shop.
Rate (N/mm)

Specification

48

Hard

46

Standard (Installation part at factory shipping)

44

Soft

21

Installation of Rear Cushion (Replacement from Standard Specification)
WARNING

Please make sure that installation is conducted in a dealership or installation
shop where there are technicians with special knowledge and skills.

When replacing the rear cushion, conduct tuning of the motorcycle posture with the following ways.

Measuring Vehicle Height Before Replacement
1. While placing a motorcycle on the ground, measure the distance from the axle shaft of the rear
wheel to the top frame, and record the value.
2. Measure above while a rider is on the motorcycle, and record the value.
3. Measure above by jacking up the motorcycle and the rear wheel is dropped completely, and record
the value.

Installation
1. Remove the standard rear cushion on the motorcycle.
[Note]For the removing method of the rear cushion, refer to the service manual of the motorcycle manufacturer.
2. Attach the A-KIT rear cushion to the motorcycle.
[Note]
 For the installation method of rear cushion, refer to the service manual of the motorcycle manufacturer.
 For the tightening torque of each bolt, refer to the service manual of the motorcycle manufacturer.

Measuring Vehicle Height After Replacement

WARNING

After replacement, the caster angle of the front fork is changed from the
pre-replacement state. If ridden in this condition, it is very dangerous because
the motorcycle behavior may be unstable and the brake performance may
change. Before riding, make sure to tune the motorcycle posture.

Measure as before replacement, and adjust the spring preload to be the same value before replacement(see page 24).
CAUTION

 Conduct vehicle height tuning at installation with the spring preload.
 If tuning is difficult, contact your nearest dealership or installation shop that
handles SHOWA products.

22

Replacement Method of Spring on Rear Cushion
Removal● Removing the spring

1. Measure and record the spring installation
length.

243mm

2. Compress the spring  with the spring
compression tool, and remove the stopperring B  and SPG seat B .
3. Remove the spring .

Installation● Attaching the spring
1. Attach the spring .

23

Replacement Method of Spring on Rear Cushion
2. Attach the SPG seat B .

3. Compress the spring to lower the SPG seatB , and attach the stopper ring B .
[Note]
After removing the SPG compression, checkthe stopper ring B  is completely set on
the groove  of the SPG seat B .

4. Turn the SPG seat to reach the spring
length measured and recorded at disassembling or it becomes the spring length
specified below. See “● Adjusting the spring
installation length” (Page 21).
[Note]
Spring installation length: 243 mm
5. Maintain the band, and tighten the bolt with the specified torque.
Tightening torque: 5 N•m24

Troubleshooting of Rear Cushion
Symptom

Cause

The rear cushion is soft.

Inadequate damping force tuning.

Tune suspension.

The gas filling pressure is low.

Stop using immediately, andcheck at the dealership or installation shop.

Settling of the spring.

Replace spring.

Bent of the rod.

Stop using immediately, andcheck at the dealership or installation shop.

Grease shortage of the cushion
bearings.

Stop using immediately, andcheck at the dealership or installation shop.

The gas filling pressure is high.

Stop using immediately, andcheck at the dealership or installation shop.

Damage.

Stop using immediately, andcheck at the dealership or installation shop.

Abrasion of the cushion bearings.

Stop using immediately, andcheck at the dealership or installation shop.

The rear cushion is hard.

Noise of the rear cushion.

25

MeasuresGP Series A-KIT for KTM
Owner’s Manual©SHOWA CORPORATION,
November, 2019, All rights reserved.
Any reprinting or unauthorized
use without the written permissionof SHOWA CORPORATION is
prohibited.
Printed in Japan