KTM 125 SX 2013 Motorcycle Suspension Upgrades

CALCULATE SPRING RATES

This is a recommendation only please consult your manual

Ideal Fork Rate:

kg/mm ( N/mm)

Ideal Shock Rate:

kg/mm ( N/mm)

BIKE DETAILS

Stock Fork Spring Rate

0.44

Stock Shock Spring Rate

48 N/mm

Bike Type

MX

Ideal Rider Weight

80 kg

Engine Specifications

2 Stroke Engine 125 cc

FORKS INFO

Fork Manufacturer

: WP USD 48 mm OD

Fork Dimensions

Compression Nut Torque: 25 in-lb (0.29 kgf-m)
Fork Travel: 283 mm

Fork Features

Preload Adjuster: 0 mm Range
Twin Chamber Fork: Yes

Fork Oil

Fork Oil Weight: SAE 5
Fork Oil Level: 360cc mm
Oil Quanity: 2 Litres

Fork Spring Information

Spring Rate – Claimed: 4.2N
Standard Preload: 8 mm

Fork Comments

: We suggest 22-25 psi bladder pressure

SHOCKS INFO

Shock Manufacturer

WP: 50 mm ID

Shock Dimensions

Nitrogen Pressure: 150 psi
Shock Travel: 110 mm
Shock Shaft Outer Diameter: 18 mm
Standard Sag: 105-115 mm
Shaft Nut Torque: 25 ft-lbs (34 NM)
Shock Oil: 5 Weight
Standard Preload: 7-8mm

Shock Features

Non-rebuildable: No

Shock Spring Information

Spring Rate - Claimed: 48 N/mm kg/mm

Shock Comments

: Spring rates from WP official

CHASSIS PARTS

11 Parts

Please wait, loading parts....

FORK REBUILD KITS

6 Parts

Please wait, loading parts....

FORK UPGRADE PARTS

4 Parts

Please wait, loading parts....

FORK SPRINGS
Ideal Fork Rate for kg: kg/mm ( N/mm)

3 Parts

Please wait, loading parts....

FORK SEALS & BUSHES

14 Parts

Please wait, loading parts....

SHOCK UPGRADE PARTS

8 Parts

Please wait, loading parts....

SHOCK SPRINGS
Ideal Spring Rate for kg: kg/mm ( N/mm)

3 Parts

Please wait, loading parts....

SHOCK BLADDER PARTS

3 Parts

Please wait, loading parts....

SHOCK SEAL CASE PARTS

7 Parts

Please wait, loading parts....

SHOCK PISTON PARTS

2 Parts

Please wait, loading parts....

TOOLS & LUBRICANTS

29 Parts

Please wait, loading parts....

Browse All 87 Products for KTM 125 SX 2013

RCU RESERVOIR BLADDER CONVERSION 54.00mm WP PDS/ LINK>2015

K-Tech

RCU RESERVOIR BLADDER CONVERSION 54.00mm WP PDS/ LINK>2015

(SKU: 211-900-115)

$179.95
2 In Stock

Teflon Shaft Bushing - 18 x 20 x 12

Teknik Motorsport

Teflon Shaft Bushing - 18 x 20 x 12

18mm id x 20mm od x 12mm Length
(SKU: 22-080-01)

$2.75
122 In Stock

Bump Stop Rubber 18 x 57 x 55 (WP 5018 1077)

Teknik Motorsport

Bump Stop Rubber 18 x 57 x 55 (WP 5018 1077)

18mm id x 57mm od x 55mm tall - WP Early Linkage
(SKU: 22-287-00)

Height H (mm): 64.0

Outside Ø D (mm): 59.0

$22.00
320 In Stock

Shock Oil Seal 18 x 30 x 5 Viton Hi Performance

Capelli Race

Shock Oil Seal 18 x 30 x 5 Viton Hi Performance

18mm id x 30mm od x 5mm thick - WP/Showa
(SKU: 22-406-00)

Oil Seal Inside Diameter d (mm): 18.0

Oil Seal Outside Ø D1 (mm): 30.0

Oil Seal Height H (mm): 5.0

$27.50
1482 In Stock

Nitrogen Shock Filling Valve M5

Teknik Motorsport

Nitrogen Shock Filling Valve M5

Standard M5 0.8mm thread - WP replacement
(SKU: 22-600-00)

$20.00
95 In Stock

WP Regas Valve (M5x0.8 Schrader)

Teknik Motorsport

WP Regas Valve (M5x0.8 Schrader)

Suits WP Shocks
(SKU: 22-600-09)

$30.80
669 In Stock

WP Front Fork DIY Service Kit - 48mm Forks

Capelli Race

WP Front Fork DIY Service Kit - 48mm Forks

(SKU: 24-374-01)

Fork Inner Tube Ø d (mm): 48.0

$169.95
59 In Stock

Outer Guide Bush 48 x 12 x 2.0 Aftermarket

Teknik Motorsport

Outer Guide Bush 48 x 12 x 2.0 Aftermarket

48mm id x 12mm tall x 2.0mm thick
(SKU: 24-580-01)

Inside Diameter d (mm): 48.0

Fork Inner Tube Ø d (mm): 48.0

Height H (mm): 12.0

Outside Ø D (mm): 52.0

Wall Thickness (mm): 2.0

$6.60
77 In Stock

WP Viton Cartridge Rod Seal (48600829)

WP Genuine Parts

WP Viton Cartridge Rod Seal (48600829)

12mm id x 17mm od x 3.5mm tall - Twin Chamber
(SKU: 24-703-08)

Inside Diameter d (mm): 12.0

Height H (mm): 3.5

Outside Ø D (mm): 17.0

$33.00
90 In Stock

48mm WP Stainless Steel Fork Seal Clip replaces WP 48600070

Teknik Motorsport

48mm WP Stainless Steel Fork Seal Clip replaces WP 48600070

fits all WP 48mm forks
(SKU: 24-750-14)

$22.00
91 In Stock

WP High Speed Adjuster Spring

Teknik Motorsport

WP High Speed Adjuster Spring

(SKU: 30-002-15)

$27.50
7 In Stock

Spring Perch Kit - All WP Bladder Forks

Suspension Direct International (SDI)

Spring Perch Kit - All WP Bladder Forks

125/150/250 SX & 250/450 SXF & TC 250/450 & FC/FE 250
(SKU: 30-004-38)

$176.00
3 In Stock

© 2025 Teknik Motorsport Pty Ltd. ABN: 29137380324. All rights reserved.

Welcome to our website. If you continue to browse and use this website, you are agreeing to comply with and be bound by the following terms and conditions of use, which together with our privacy policy govern Teknik Motorsport Pty Ltd’s relationship with you in relation to this website. If you disagree with any part of these terms and conditions, please do not use our website.

The term ‘Teknik Motorsport Pty Ltd’ or ‘us’ or ‘we’ refers to the owner of the website whose registered office is 4/5 Harford St, JAMISONTOWN, NSW, 2750, AUSTRALIA. Our ABN is 29137380324. The term ‘you’ refers to the user or viewer of our website.

The use of this website is subject to the following terms of use:

The content of the pages of this website is for your general information and use only. It is subject to change without notice.
Neither we nor any third parties provide any warranty or guarantee as to the accuracy, timeliness, performance, completeness or suitability of the information and materials found or offered on this website for any particular purpose. You acknowledge that such information and materials may contain inaccuracies or errors and we expressly exclude liability for any such inaccuracies or errors to the fullest extent permitted by law.
Your use of any information or materials on this website is entirely at your own risk, for which we shall not be liable. It shall be your own responsibility to ensure that any products, services or information available through this website meet your specific requirements.
This website contains material which is owned by or licensed to us. This material includes, but is not limited to, the design, layout, look, appearance and graphics. Reproduction is prohibited other than in accordance with the copyright notice, which forms part of these terms and conditions.
All trademarks reproduced in this website, which are not the property of, or licensed to the operator, are acknowledged on the website.
Unauthorised use of this website may give rise to a claim for damages and/or be a criminal offence.
From time to time, this website may also include links to other websites. These links are provided for your convenience to provide further information. They do not signify that we endorse the website(s). We have no responsibility for the content of the linked website(s).
Your use of this website and any dispute arising out of such use of the website is subject to the laws of Australia.

This privacy policy sets out how we use and protect any information that you give us when you use this website.

We are committed to ensuring that your privacy is protected. Should we ask you to provide certain information by which you can be identified when using this website, then you can be assured that it will only be used in accordance with this privacy statement.

1. WHAT WE COLLECT

We may collect the following information:

name and job title
contact information including email address
demographic information such as postcode, preferences and interests
other information relevant to customer surveys and/or offers

2. WHAT WE DO WITH THE INFORMATION WE GATHER

We require this information to understand your needs and provide you with a better service, and in particular for the following reasons:

Internal record keeping.
We may use the information to improve our products and services.
We may periodically send promotional emails about new products, special offers or other information which we think you may find interesting using the email address which you have provided.

3. SECURITY

We are committed to ensuring that your information is secure. In order to prevent unauthorised access or disclosure, we have put in place suitable physical, electronic and managerial procedures to safeguard and secure the information we collect online.

We take all reasonable steps to keep secure any information which we hold about you.
Personal information may be stored both electronically on our computer system, and in hard-copy form.
Firewalls, 2048 Bit v3 SSL encryption, passwords, anti-virus software and email filters act to protect all our electronic information.
We do not store credit card information, we securely submit credit card information to our bank for processing.
We will not sell, distribute, lease or disclose your personal information to third parties (unless we are required by law to do so).
We may use your personal information to occasionally send you promotional information about our products and services which we think you may find interesting.
Should you wish to have your personal information removed or updated, or you would like to stop receiving advertising please CONTACT US.

4. HOW WE USE COOKIES

A cookie is a small file which asks permission to be placed on your computer's hard drive. Once you agree, the file is added and the cookie helps analyse web traffic or lets you know when you visit a particular site. Cookies allow web applications to respond to you as an individual. The web application can tailor its operations to your needs, likes and dislikes by gathering and remembering information about your preferences.

We use traffic log cookies to identify which pages are being used. This helps us analyse data about webpage traffic and improve our website in order to tailor it to customer needs. We only use this information for statistical analysis purposes and then the data is removed from the system.
Overall, cookies help us provide you with a better website by enabling us to monitor which pages you find useful and which you do not. A cookie in no way gives us access to your computer or any information about you, other than the data you choose to share with us.
You can choose to accept or decline cookies. Most web browsers automatically accept cookies, but you can usually modify your browser setting to decline cookies if you prefer. This may prevent you from taking full advantage of the website.

LINKS TO OTHER WEBSITES Our website may contain links to other websites of interest. However, once you have used these links to leave our site, you should note that we do not have any control over that other website. Therefore, we cannot be responsible for the protection and privacy of any information which you provide whilst visiting such sites and such sites are not governed by this privacy statement. You should exercise caution and look at the privacy statement applicable to the website in question.

5. CONTROLLING YOUR PERSONAL INFORMATION

You may choose to restrict the collection or use of your personal information in the following ways:

whenever you are asked to fill in a form on the website, look for the box that you can click to indicate that you do not want the information to be used by anybody for direct marketing purposes
if you have previously agreed to us using your personal information for direct marketing purposes, you may change your mind at any time by CONTACTING US.