XACT & AER48 with Revalve Control

Maximum performance and versatility

This is, hands down, the best suspension I've ever ridden ... I'm blown away!

-David Pingree, Racer X Illustrated

Click to watch the full video review

2017 Husqvarna FC 450 with Kreft Moto suspension, including AER Revalve Control, Shock Revalve, and Microfinishing.

Revalve Control technology is available exclusively from Kreft Moto.

Revalve Control technology is available exclusively from Kreft Moto.

Our air spring modifications make the XACT/AER48 more reliable, more plush, and settle the front end for improved cornering.

Stock XACT/AER48 Fork

Kreft Moto has identified the following performance issues with the stock XACT/AER fork:

  • Hyper-progressive spring curve. XACT/AER48 relies largely on spring force to control travel usage and prevent bottoming. While the fork has excellent bottoming resistance, this approach has drawbacks. Spring force is position-sensitive, not speed-sensitive, so the fork exerts the same force at a given point in the travel regardless of the size of the bump. Shim-controlled valves have the unique ability to create damping force in proportion to the impact force, which is a great advantage in dissipating the energy efficiently – which is to say, in the plushest way possible. The highly progressive spring curve is a major reason why XACT/AER48 feels plush at the top of the stroke, but harsh deeper in the travel.

  • Rides too high in the stroke. For the reasons described above, AER48 needs to ride high in the stroke to feel compliant. However, the excessively tall ride height causes poor cornering traction, inaccurate line tracking, and an unsettled, "dancy" feel at the front wheel.

  • Oversimplified mid-valve (XC and XC-F models). AER48 uses a check spring type mid-valve in place of a traditional shim stack. A single wave spring and check shim controls fluid flow through the valve. This configuration reduces assembly time, but also reduces consistency, durability, and our ability to tune the valve. It also contributes to a "blow-off" feel that makes the fork less sensitive to small bumps but use travel rapidly on larger impacts (again, relying on the air spring to control travel usage).

  • Air spring failures (2016.5 and 2017 models). AER48 uses a poorly designed air spring piston seal, which can lead to air spring failure.


XACT/AER Spring Force
Before and After Kreft Modification

The stock air spring has too much progression in the second half of the stroke. We modify the spring curve to mimic a coil-sprung fork.

Our Solution

Kreft Moto’s performance tuning for the WP XACT & AER48 includes the following improvements:

  • Revalve Control. Our revolutionary external revalve system.

  • Kreft custom valving. Meticulously engineered, with critically-acclaimed performance.

  • Neutral ride height. Our revised spring curve and damping modifications allows us to specify lower air pressures and create a more free-moving feel in the initial stroke. The added negative travel enhances traction by helping the wheel remain in contact with the ground. It also improves cornering confidence with a reliable turn-in feel and calm, "no-hands" line tracking.

  • Linear spring curve. Modification of the air spring element makes the air spring curve mirror a coil-sprung fork for a more consistent feel, with improved plushness at middle stroke and deeper.

  • Refined mid-valve (XC and XC-F models). By replacing the check shim with a traditional multi-layer shim stack tuned to our specifications, we can control compression damping with much greater precision.

  • New air spring piston seal (2016.5 and 2017 models). Our seal eliminates air spring failures.

Revalve Control (Patent Pending)

Kreft Moto's XACT/AER48 brings with it a revolutionary new suspension technology called Revalve Control.  This technology makes it possible to alter the fork's shim valving stiffness by means of an external adjustment.  Riders have long wished for "external revalve" system, and this is it – the first and only motorcycle fork with that capability.  Revalve Control provides riders with two key advantages never before available:

  • Terrain Versatility

  • Insight

Terrain Versatility
The obvious benefit of being able to revalve your suspension so easily is the terrain versatility it adds.  While traditional suspension "clickers" are good for fine-tuning, they are not capable of substantial changes to the damping curve.  Revalve Control can completely transform the fork – from Enduro to MX, or from rocks to sand, or from beginner to pro.

The other benefit of Revalve Control is the opportunity to experience and identify your true suspension preferences.  Professional riders work on-on-one with a suspension tuner to hone in on the performance characteristics that help them ride with the greatest confidence and control.  While very few of us have that luxury, Revalve Control places the same power in the hands of any rider.

As a suspension tuner, the hardest part of my job is interpreting the customer's comments into a valving setting that aligns with his desired riding experience.  Many customers have trouble articulating the suspension feel they are looking for, or in other cases the tuner develops an inaccurate picture of the rider's terrain, skill level, and riding style.  Both scenarios result in a flawed suspension setting.  Revalve Control is forgiving of this difficulty.  For example, if Kreft Moto's original setting proves to be less than ideal, Revalve Control gives us tremendous power to resolve the complaint from a distance.

Settings Tables

You will not be lost or overwhelmed by this new tuning power.  Kreft provides a detailed settings chart to every customer, to help guide you tuning for a wide range of applications and ability levels.  Information for both fork and shock is provided.  With Revalve Control on the fork, we are free to make full use of the shock's high speed compression adjuster without danger of unbalancing the chassis.

Example enduro settings table

Example enduro settings table

Example motocross settings table

Example motocross settings table

Technical information

Click HERE for a more detailed explanation of how Revalve Control works.




  • Kreft Moto's AER48 Revalve Control system with independent compression, rebound, and Revalve Control adjusters

  • Revalve Control settings table - a guide to tuning your suspension for optimal performance in different conditions

  • Custom valving setting adapted to each customer

  • Air spring modification for a more linear spring curve - like a coil spring fork

  • Nitrogen-charged air spring element for pressure stability

  • Replacement of air spring piston seal with a more reliable design (2017 models)

  • Cleaning, inspection, and replacement of wear parts where required

  • Note: cost of wear parts and fluid not included


Optional Performance Upgrades


Applicable Models

  • 2017 - 2020 KTM SX, SX-F, XC, & XC-F

  • 2017 - 2020 Husqvarna TC, TX, FC & FX

  • 2016.5 & 2017.5 KTM Factory Edition 250 and 450


The AER48 Revalve Control assembly prior to installation

Silent and durable nitrile top-out bumper

Concentric Revalve Control and rebound adjusters. The low-speed compression clicker is located on the fork cap.


AER48 Revalve Control Adjustment Range

AER48 Stock Compression Adjustment Range

Revalve Control determines the shape and position of the damping curve (click for larger view).

The stock compression adjuster is retained for fine-tuning of low-speed compression damping (click for larger view).


Start the Process: