Referring to Rekluse’s “auto clutch” systems is much more simply stated than achieved. Auto clutch technology has been meticulously engineered, tested, and developed through several generations in the engines of many different brands and types of motorcycles. But, what are the benefits of running an auto clutch in the first place?

Benefits of an Auto Clutch and How it Works

Swing a leg over a motorcycle equipped with a Rekluse auto clutch system – whether it be a RadiusX or RadiusCX – and roll on the throttle and riders will notice they can start and stop without the clutch lever. The automatic engagement and disengagement of the clutch is based on engine RPM, allowing the EXP disk to perform what you’d normally do by pulling in the lever, on its own. This eliminates stalling and improves rider control, maximizing traction and confidence to navigate challenging terrain. Plus, riders can run a gear taller, allowing the suspension and chassis to settle and work better.

KTM Off-road EXP 4.0
Auto clutch systems can provide a wide range of benefits outside of just eliminating stalling.

The EXP disk is the magic ingredient behind the functionality and benefits of Rekluse auto clutches. About 10 years ago, Rekluse introduced an innovatively redesigned version of its revolutionary auto clutch technology with EXP 3.0. The years of racing, testing and development since have led to Rekluse’s most refined auto clutch experience yet; Introducing EXP 4.0. Rekluse engineers went through every aspect of the EXP auto clutch disk design to achieve three major goals: More direct power delivery, improved durability, and rider-focused functionality.

Shop RadiusX and RadiusCX clutch systems featuring EXP 4.0 for your bike below.

How Can you Upgrade Your Rekluse 3.0 Auto Clutch to 4.0?

If your bike is already equipped with a Rekluse auto clutch system using EXP 3.0 - whether it be RadiusX, RadiusCX, or Core EXP 3.0 - there's a quick and convenient option for you. Depending on your system, you have the choice of purchasing an EXP 4.0 assembly on its own, or an EXP 4.0 assembly plus a fresh clutch pack with complete with drive plates and TorqDrive friction disks and baskets (for applicable models).

The upgrade is simple! Backwards compatibility with Rekluse 3.0 systems is drop-in ready; Simply replace your EXP 3.0 disk with your new EXP 4.0 disk and you're ready to enjoy all the advantages of the latest generation auto clutch.

EXP 4.0 auto clutch disk
EXP 4.0 was designed and tested to achieve three goals: More direct power delivery, improved durability, and rider-focused functionality.

What Changes were made with EXP 4.0 from EXP 3.0?

First, the base material used for EXP 4.0 has been updated to provide better strength in high temperature environments, critical for the heat clutch systems create. Next, the internal wall of EXP 4.0 bases were redesigned for strength and rigidity, which helps translate to a more connected lever feel for the rider.

EXP 4.0 bases
EXP 4.0 improvements started at the bases, using improved material and design for provide better strength in the harsh environments of clutch systems.

On the outside of the EXP disk, riders will notice the friction pads now match the proprietary friction design found on Rekluse TorqDrive clutch plates. Applying this friction pad design helps match oil flow characteristics of the clutch pack beneath, promoting improved cooling capability and consistent operation.

EXP 4.0 TorqDrive friction pad design
EXP 4.0 uses a TorqDrive friction pad design, improving oil cooling and flow, improving longevity.

The ‘wedges’ are a critical component to the centrifugal functionality of EXP 4.0. In the previous iteration, the wedges would slide up and down ramps built into the EXP bases to engage and disengage the clutch. EXP 4.0’s wedge has been improved to now use rolling contact with built-in pins. Rolling versus sliding creates less friction and resistance, providing smoother engagement and a more responsive feel, creating stronger power delivery overall.

EXP 4.0 wedges
EXP 3.0 vs. EXP 4.0

The wedge and ramp design of EXP 4.0 has been improved with rolling action vs. sliding, creating less friction and resistance for more direct power delivery and smoother engagement.

Not only is engagement smoother and more responsive, but the engagement curves of EXP 4.0 have been designed to better match the engine characteristics of modern motorcycles. Improved tuning options play a role in this as well, as riders now have the option to set up their EXP 4.0 with a combination of light, medium and heavy wedge weights in addition to having multiple EXP disk spring options as they did with 3.0. This creates much more potential for riders to optimize their clutch and engine characteristics based on riding conditions. However, if you’re a rider that likes load-up and go, EXP 4.0 comes with recommended settings out of the box.

EXP 4.0 KTM 350
EXP 4.0 bike test group

EXP 4.0 disks were developed and tested to complement the engine characteristics of a wide variety of modern bikes.

EXP 4.0 will be featured in all new RadiusX and RadiusCX auto clutch kits going forward, and will also be retrofitted to those same kits as they are restocked for existing models. Any riders that currently have a Rekluse auto clutch system with EXP 3.0 can quickly and easily upgrade to EXP 4.0 with a simple disk swap and adjustment check.

Summing it Up: Rekluse EXP 4.0 Auto Technology Benefits

  • More direct power delivery, improved durability, and rider-focused functionality
  • Upgraded base material providing improved strength at high temperatures
  • Revised base design improving strength and rigidity, translating to more connected lever feel
  • Improved wedge design with pins allows for rolling instead of sliding to expand the disk, creating a more responsive feel and smoother engagement
  • TorqDrive friction pad design matches revised oil flow characteristics
  • Engagement curve designs updated to better match modern motorcycle engine characteristics
  • More tuning options with varying wedge weights and EXP springs
RadiusCX clutch with EXP 4.0
RadiusCX auto clutch kit with EXP 4.0 technology.