Krooztune
WP AER48 Air to Spring Conversion Kit (ATS)
Single spring availble here : ATS Spring only
Introducing the KTM and Husqvarna WP48 Air to Spring Conversion Kit - the perfect upgrade for all KTM and Husqvarna models equipped with WP48 AER forks as standard. This kit is specifically designed to fit KTM's SXF, SX, XC, and XCF models, as well as Husqvarna's FC, TC, TX, and FX bikes.
If your bike comes with WP AER48 forks as original equipment, this conversion kit is an excellent choice. Say goodbye to the hassle of adjusting air pressure and experience a significant improvement in front-end feel, corner entry, and ride quality over long distances. The kit eliminates the need for air pressure adjustments and provides a more consistent spring rate for a smoother ride. Don't let variable pressure ruin your ride - upgrade to the KTM and Husqvarna WP48 Air to Spring Conversion Kit today.
Install Video:
Our WP Air to spring conversion kit is a complete replacement cartridge assembly for your current WP AER setup. It is designed to completely remove all the Air system from your current WP AER 48 fork and replace it with a preload adjustable spring and cartridge setup. High Quality German Engineered ‘Eibach’ Springs are available to suit varying rider weights. Please advise upon order which spring you require (see recommendations below) or let us know your weight and speed and we will recommend the best spring for you.
This kit fit's in minutes. If you can pull down and service your fork seals on the WP AER 48 fork you can install this kit. Info and instruction included.
Spring Rate Recommendation
250F and 2 Strokes
| KG | LBS | Recommended Spring Rate | Pro or A grade |
| <60kg | <130 | 0.80 kg/mm | 0.84kg/mm |
| 60-65kg | 130 -140 | 0.84kg/mm | 0.88kg/mm |
| 65-75kg | 140-165 | 0.88kg/mm | 0.92kg/mm |
| 75-85kg | 165-185 | 0.92kg/mm | 0.96kg/mm |
| 85-95kg | 185-205 | 0.96kg/mm | 1.00kg/mm |
| 95-100kg | 205-220 | 1.00kg/mm | 1.04kg/mm |
| 100-110kg | 220-240 | 1.04kg/mm | 1.08kg/mm |
| 110kg+ | 240+ | 1.08kg/mm | 1.08kg/mm |
450F
| KG | LBS | Recommended Spring Rate | Pro or A grade |
| <60kg | <130 | 0.84 kg/mm | 0.84kg/mm |
| 60-65kg | 130 -140 | 0.88kg/mm | 0.88kg/mm |
| 65-75kg | 140-165 | 0.92kg/mm | 0.96kg/mm |
| 75-85kg | 165-185 | 0.96kg/mm | 0.98kg/mm |
| 85-95kg | 185-205 | 1.0kg/mm | 1.04kg/mm |
| 95-100kg | 205-220 | 1.04kg/mm | 1.04kg/mm |
| 100-110kg | 220-240 | 1.04kg/mm | 1.08kg/mm |
| 110kg+ | 240+ | 1.08kg/mm | 1.08kg/mm |
General riding & Motocross applications
These recommendations are a guide only as fork Springs are weight and speed dependent. For example a 72 kg Pro rider falls into the 0.88kg/mm category but may well be better suited to a 0.92kg spring due to the much higher corner entry speed and the ability to hit large bumps at high speeds. Please note this guide is for rider weight ‘without’ gear.
Please note we have had great results using one spring down for Veteran/ C level riders on the 450 machines. Eg. 90kg rider running a 0.96kg/mm spring for a plusher ride.
For more accurate advice please consult your local suspension tech or send us an email.
Rider weight Spring Recommendation ( Pro Level riders may consider one rate harder than recommended due to the faster speed and need for 'hold up')
Key Features
- Never have to set your air pressure ever again.
- Much more reliable fork
- Super smooth action resulting from our tested spring guidance system.
- Hydraulic Bottoming resistance using our tapered bottoming piston and seat.
- No Fade out or pump up in pressure over long moto’s
- A Constant feel in your front end that is more consistent throughout the ride
- Spring Pre load adjustable minimal tools are required for fitment. If you have the Fork cap and basic tools to remove the standard OEM Air cartridge you will have the ability to fit up our kit. Our cartridge kit is made from High grade 6061 Aircraft Grade Alloy , Chrome Moly rods and Anodised for a Factory Finish. Instruction manual included.
Parts included in the kit
- Fully Complete Cartridge assembly including Bottoming Cone and preload washers
- Optional Selected Eibach spring to suit this kit
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Product information
PRODUCT FEATURES
Get Your Perfect Setup
Not sure which setting, kit level or upgrade is right for your bike?
We’ll match your suspension to your weight, speed and riding style using real data and years of race-proven experience.
Submit your details and we’ll guide you to the ideal setup.
F.A.Q.
They appreciate cut and details, things that aren't so obvious.
Do you offer setup advice with this product?
Absolutely.
Every purchase includes access to our Setup Form, where we provide personalised guidance on your ideal settings, spring rates, and upgrade choices.
Can I purchase items with another currency?
Yes, you may select a currency based on your personal preference. When you select your country in the country selector and set to your country’s version of the website, you will see prices listed in the regional currency.
Can I make changes to my order after it’s been placed?
Email Info@krooztune.com asap and quote your order number. Our emails are checked daily before shipping out any orders
What if I have issues or need support after buying?
We’re here to help.
You can reach us anytime for setup adjustments, technical questions or installation support. Krooztune products are backed by real riders and real workshop support.
Do I need to pay extra tariffs or taxes when ordering from the USA?
No — Krooztune covers all USA tariffs and import taxes.
The price you see at checkout is final, with no hidden fees or surprise charges upon delivery.
