TEN THINGS ABOUT AUTO CLUTCHES

 

TEN THINGS ABOUT AUTO CLUTCHES

(1) Auto clutches. An auto clutch automatically engages and disengages the clutch based on the engine’s rpm and the power being relayed to the transmission. With an auto clutch installed, riders are still able to engage and disengage the clutch normally through actuation of the clutch lever; however, rider modulation of the clutch isn’t necessary in many situations. With an auto clutch installed, riders can start and stop without ever touching the clutch lever.

(2) Performance benefits. Many riders found that they worry less about the possibility of stalling the engine when using an auto clutch. This allows them to go faster, because they have more brain power to focus on line choice, body position and other aspects of riding. Riders also enjoy being able to use a higher gear in corners without the fear of stalling. Riding a gear higher allows the suspension to settle better, ride smoother over bumps and gain traction in slick sections of the track. Because the riders are still able to actuate the clutch manually, tests have been done where riders didn’t even notice that they had an auto clutch installed. 

(3) Options. Rekluse is the only manufacturer that currently produces auto clutches for motocross bikes. They offer the RadiusX, CoreEXP 3.0 and RadiusCX models, and they each come with a 30-day money-back guarantee. The Rekluse auto-clutch system is available on both cable and hydraulic fluid clutch operating models.

(4) Race ready. Previously, auto clutches were thought of as a trail riding accessory, but now they are becoming more popular in Supercross and motocross as well. In 2019, Star Racing Yamaha rider Dylan Ferrandis used RekluseCX auto clutches for the entire AMA outdoor National season, and he earned his first win with the auto clutch at the Red Bud National when he scored 1-1 moto finishes while using the same clutch plates for the entire race day. 

Rekluse adjustable slave cylinder.
Rekluse adjustable slave cylinder.

(5) How it works. Using principles of centrifugal force, the auto clutch automatically engages and disengages the clutch based on engine rpm. The Rekluse auto clutch uses an EXP disc to create this auto function. When you turn the throttle on and the auto clutch spins up to a pre-set rpm, at that point the centrifugal weights inside the clutch pack move outward to engage the drive plates and keep them hooked up until you let the rpm drop to a level where the weights retract to disengage the clutch. This process allows you to start, stop and ride your motorcycle without touching the clutch lever. 

(6) Slipper clutch. An auto clutch should not be confused with a slipper clutch. When aboard a slipper clutch-equipped machine, deceleration will disengage the clutch (very much like pulling the clutch in on the entrance to a turn); however, a slipper clutch will not prevent stalling because it does not keep the clutch disengaged. Slipper clutches were designed to limit wheel hop on deceleration, and Supermoto racers used slipper clutches to keep their bikes from chattering under hard braking on pavement. In motocross, a slipper clutch is used more as a suspension mod that helps keep the rear suspension from locking up in braking bumps.

(7) Rekluse EXP disc. The EXP disc is the magic behind the Rekluse auto clutch. This piece essentially takes over for your left hand and does all of the clutch work for you. It acts as a friction disc that responds to engine speed. When the motorcycle reaches the pre-set rpm, the EXP disc is spinning and the centrifugal force causes the weights to slide out. Because the weights are wedge shaped, they expand the disc as they move outward. This causes the disc to take up the free space between the plates and engage the clutch. The point at which the clutch engages can be fine-tuned with different wedges, springs and idle speeds for a customized feel.

Rekluse Clutch Yamaha YZ250F testing

(8) Adjustment. For the cable-clutch operated models, Rekluse offers internal and external adjustability. The internally adjusted auto clutch is the most popular for motocross and off-road riding because the lever retains the same feel of a manual clutch and because the maintenance is much less. The benefit of an externally adjusted auto clutch is that it can be adjusted on the fly. This helps riders who are hard on clutches or riders who are competing in a mud race. On hydraulic clutches, Rekluse offers a clutch slave unit that allows the throw of the clutch push rod to be adjusted with an Allen wrench. 

(9) Shifting. Auto clutches do not turn your manual transmission into an automatic transmission. Shifting will still need to be done at the shift lever. The difference is that you don’t have to worry about stalling or modulating the clutch to get into the meat of the power.

(10) Durability. With the clutch being mechanically engaged at the same rpm every time, clutch wear is consistent, which prolongs the clutch’s lifespan. Similar to stock OEM clutch applications, the durability depends on how aggressive the rider is. Auto clutches are designed to last at least as long as a standard OEM clutch. Auto clutch durability also depends on ensuring that the clutch is within spec and is adjusted correctly.

You might also like