Feb 25, 2019
Different machines, types of riding, and skill levels may benefit from different clutch setups. So how do you decide which clutch is right for you? Here, we break down each of Rekluse's clutch offerings to help you make an informed decision.
While riding a motorcycle may seem elementary to an experienced individual, it’s not the act of riding that’s so impressive as how a motorcycle works. Very few people take to the time to think about all of the minute steps required for a bike to even start, let alone be ridden. Of course, there’s the piston pumping up and down, fuel igniting in the combustion chamber, and the crankshaft turning energy into rotary motion. One of the most overlooked components of an engine is the clutch system. In fact, it’s generally considered an afterthought; that is, until it stops functioning properly.
Motorcycle enthusiasts may view the engine’s clutch as a small piece of a large puzzle, unnecessary to worry about until new clutch plates are required. However, the clutch can actually be a huge performance advantage. Rekluse, an Idaho-based company that has been making their own line of clutch systems for 17 years, knows this all too well. Their first centrifugal automatic clutch (known as the Z-Start), put them on the map. Top off-road racers across various disciplines have raced, and won, with the Rekluse auto clutch. As an aftermarket company, reaching the pinnacle of the sport can’t be accomplished by offering an inferior product. Every component is tested to its maximum capabilities before ever being used in a race situation.
Rekluse offers six different options across the auto and manual clutch categories for dirt bikes. Although known for their automatic clutch systems, Rekluse makes state-of-the-art manual clutch packages. Which one is right for you? Auto or manual? RadiusCX or EXP 3.0? Core Manual TorqDrive or Core Manual? Read on to find out.
Understand Your Options
Think about your preferences, expertise, and shortcomings as a rider. Are you a beginning motocross racer, focused on mastering throttle control and maintaining corner speed? Perhaps you’re an avid trail seeker, searching for unconquered terrain in the most hostile environments. Whatever the case, it’s important to understand that your bike’s clutch can either help or hinder your goals as a rider. Understand that you have options.
Conventional clutch systems can be easily abused, leading to premature wear and eventual failure. Constantly pulling in and releasing a clutch lever causes fatigue. Automatic clutches can help solve those problems. Is there a drawback to using an auto clutch? Some may find the technology foreign, requiring practice in order to achieve comfort. Wrap your head around the idea of coming to a stop with the bike in gear and your hand off the clutch. Fortunately, Rekluse covers the spectrum of clutch configurations.
Through extensive research and development, Rekluse created three technological advancements that are shared among various clutch systems in their line. These components are a telling sign of Rekluse’s commitment to achieving clutch mastery.
The Houdini of clutch tech, Rekluse’s EXP disk is responsible for engaging and disengaging the clutch based on centrifugal force. When the motorcycle reaches a certain rpm, the EXP wedges slide out to expand the disk and engage the clutch. All of this is happening from engine idle to about 3,000 rpm. The point at which the clutch engages can be fine-tuned with different wedges and springs for a customized feel.
Austin Paden, Rekluse Product Manager/Race Development, elaborates, “There was a lot of thought that went into the ramp angles during the development process, and how the wedges would ramp out while rotating. Small changes to the wedges made a big difference in how the auto clutch performed. Our goal was to make something lightweight, easy to adjust, and functional.”
EXP technology is utilized on the RadiusCX, RadiusX and Core EXP 3.0 automatic clutch systems.
Exactly what the name implies, TorqDrive is based on the principle that using more friction plates in a clutch pack creates increased torque capacity. Rekluse accomplished this by decreasing the thickness of their plates in order to use more plates in the same confines, while developing their own friction material for increased durability.
Check out how TorqDrive increases torque capacity.
Paden states, “The idea was to increase torque capacity to the system. Ultimately, the goal was to allow for more tuning options, lighter feel at the lever, and lessen clutch operating temperatures. The world of Supercross and motocross is based around a standard functioning manual clutch. The market in that segment is very competitive. We learned that other companies were using standard-based friction plates. Yet race teams were still having issues with breaking friction plates and experiencing clutch fade, which was caused by expansion. Our goal was to find a fiber compound that was durable, even when the operating temperature became extremely hot, yet be thin enough to fit more fiber plates into that same working area.”
The friction plates are made out of steel, which bucks the trend of using aluminum. When subjected to extreme heat, aluminum expands roughly twice as much as steel. Expansion leads to clutch fade. Rekluse essentially solved an age-old clutch malady through metallurgy.
Additionally, the steel-based friction plates have unusually shaped friction material totally unlike a traditional square or rectangle-shape. Paden explains, “We came up with our own fiber material and design, which is based around oil flow. That material is on a steel core, which maintains its integrity, even when the engine gets really hot. As a result, you don’t get clutch fade or constantly have to adjust the clutch cable in the middle of your moto. The Rekluse TorqDrive system contains 12 friction plates in most Japanese-manufactured bikes, versus seven or eight in a OEM/stock configuration.” Additionally, the TorqDrive pack comes with steel lining clutch basket sleeves to eliminate wear and notching to the clutch basket tangs. Rekluse left no stone unturned.
TorqDrive technology can be found in the RadiusCX and RadiusX auto clutches, as well as the Core Manual TorqDrive and TorqDrive Clutch Pack manual editions.
Heat is the mortal enemy of an engine’s clutch. Rekluse confronted that problem head-on by developing their own hub, pressure plate and clutch cover. Made out of billet aluminum and designed around optimizing oil flow to lower clutch operating temperatures, Core is literally cool.
Paden states, “We made the parts lighter in order to create less rotating mass. In comparison to the competition, what’s noticeable about our hubs and pressure plates are that they have very open profiles. The bottom and top of the hub have features that basically act as a dam for the oil. Oil that makes its way into the center hub is directed through the clutch plates. More flow reduces heat. The pressure plate is also open, and any oil that comes from the front side of the clutch system makes its way to the center clutch.”
A close inspection of an OEM/stock hub will likely reveal oil holes and features that are located in the profile where the drive plates would ride. With this design, the holes are potentially blocked, preventing oil from reaching the clutch plates. Rekluse found a solution. Paden explains, “The Rekluse-designed hub has the oil holes and features on the ribs themselves. There are features in the drive plates, which act like pockets, so the oil is able to flow to the clutch plates without restriction.”
Taking it a step further, Rekluse created their own clutch cover that allows for roughly 50cc more oil capacity. More oil equals decreased operating temperature.
Core technology is utilized in RadiusCX and Core EXP 3.0 auto clutches, as well as Core Manual TorqDrive and Core Manual clutches.
Automatic: What are your Options?
RadiusCX is the Taj Mahal of automatic clutch systems, featuring a plethora of Rekluse’s latest technologies. It contains the best features, as far as cooling and auto clutch performance. If you are a clutch abuser, the RadiusCX is for you. Like the other auto clutch options, the rider can use the clutch lever for manual operation. Given that it’s full of benefits, this is also the most expensive auto clutch in Rekluse’s line.
RadiusX is the little brother to the RadiusCX. Featuring EXP and TorqDrive technology, the system comes with the EXP disk and clutch pack, as well as the clutch basket sleeves. It does not come equipped with the Core billet components however.
Core EXP 3.0 utilizes the EXP centrifugal disk, meaning that you can come to a complete stop in gear with clutch out and not stall the bike. The package also includes the Core billet parts. OEM/stock clutch plates are required with the Core EXP 3.0.
Manual: What Are Your Options?
Core Manual TorqDrive was designed for serious racers, used at the Supercross level on down to the amateur ranks. It has the most adjustments as far as tunability, and outstanding durability. The kit comes with Core and TorqDrive technology.
Core Manual is essentially a billet replacement for the stock hub and pressure plate. Some riders may prefer the feel of riding with OEM/stock friction plates. If that statement explains you, then the Core Manual is your best option.
The TorqDrive Clutch Pack takes the clutch pack used in the Core Manual TorqDrive and puts it into a stock hub and pressure plate. It’s very affordable, and a good alternative for racers on a tight budget.
What the Professionals Run
Rekluse’s list of sponsored riders reads like a who’s who in all of the major forms of two-wheeled off-road motorcycle racing series. In fact, Rekluse relies on some of the world’s best athletes for product development and durability.
Given that Rekluse produces a variety of clutch applications, it makes sense that their fleet of sponsored riders have their particular favorites. The 2018 Monster Energy Supercross Champion, Jason Anderson, along with the rest of the Rockstar Husqvarna factory team, prefers the Core Manual system, which they pair with OEM/stock fiber plates. Dean Wilson opts for the TorqDrive clutch pack, as it easily drops into a stock clutch system. The Star Racing Yamaha team has been using the full Core Manual TorqDrive kit for roughly five years. In that span, the 250 program has won championships with Cooper Webb and Aaron Plessinger.
Dubbed “Mr. Versatility” by Racer X Illustrated, Ryan Sipes has competed in a bevy of different off-road disciplines over the past few years. From ISDE to GNCC, Sprint Enduro and event Flat Track, Ryan’s clutch of choice is the RadiusCX. Another GNCC racer, Ricky Russell, has used the RadiusCX system for the past year and a half. It makes sense, given that GNCC races are gruelingly long at three hours, where hand fatigue and engine stalling can be major issues.
Paden explains that Endurocross riders tend to bounce back and forth between auto and manual clutch options. “Auto clutches were incredibly popular for several years in Endurocross, and then racers started gravitating to manual clutches. Right now, we’re in this state where guys are going back to the auto systems. It’s one of those scenarios where if one guy who is winning goes auto, the rest follow.” Given that a motorcycle clutch is a beneficial aftermarket modification, it is a change that is quickly picked up and copied by the competition.
Believe it or not, there are some riders who prefer to race Supercross with an automatic clutch. Paden explains, “I have done back-to-back testing with top privateers in Supercross, and most post faster lap times with an auto clutch. They couldn’t believe it. That’s because an auto clutch makes the bike's power feel smoother.” Smooth doesn’t feel fast to most riders, but the stopwatch doesn’t lie. Paden believes that more riders will start preferring automatic clutches in Supercross over time. It’s not a crazy theory, given that roll speed is an important part of clearing jumps and being successful in Supercross.
If you’re still unsure of which Rekluse clutch to install in your motorcycle, give the clutch experts a call at 208-426-0659, or browse the Rekluse website at www.rekluse.com.