Ktm Duke

What Is A Slipper Clutch?

Over time, new advances and modifications appear to make the riding experience of motorcycles safer and more stable. Normally, these novelties are tested exclusively by a few lucky ones who are able to obtain the most exclusive models.

An example of this was the slipper clutch that began as a system incorporated only in selected models but that over time has been able to adapt to any type of model and style, especially those which are more sporty. But do you know what the slipper clutch exactly is?

Slipper Clutch

The slipper clutch is a mechanical system used to ensure the stability of your neoclassical motorcycle in critical driving situations. This device is in charge of connecting or disconnecting the crankshaft and the gearbox; it transmits the movement of the motor shaft to the gearbox and is transmitted to the rear wheel. This is exactly what happens when you make a gear change; you disconnect the crankshaft from the gearbox so that no force is exerted, and it is easier for you to change gear. This is what a clutch itself consists of, but why do you need a slipper clutch?

Without the anti-skid system, by downshifting with many revolutions, you are forcing the rear wheel to pick up speed. If at the same time that this happens, you apply the brake, you are loading the weight of the motorcycle and that of the rider on the front wheel. This lack of weight at the rear can cause the rear wheel to spin uncontrollably, and the moment it hits the ground at a higher speed than the motorcycle’s speed, it can cause a bounce or jump.

Ktm Slipper Clutch

In addition, if you activate the rear brake forcing the wheel to reduce the speed at the same time as the engine tries to give it, you can make the wheel stay locked. And in these cases, the slipper clutch is really helpful!

How Does Slipper Clutch Help?

With a normal clutch, you can get to control the rebound if you keep it engaged for a certain distance, and you make the clutch slip. But you will not be able to eliminate them completely.

In the case of the slipper clutch, you only have to release the lever after downshifting. This system will disengage to a degree to make it skid so that the wheel does not produce that annoying bounce. The main advantage that the slipper clutch offers is that; now, you will be able to reduce gears on your neoclassical motorcycle while operating the rear brake and even the front, obtaining stable braking without any fright.

Slipper Clutch

Advantages of Slipper Clutch

With a normal clutch, you can get to control the rebound if you keep it engaged a certain distance, and you make the clutch slip, but you will not be able to eliminate them completely. In the case of the slipper clutch, you only have to release the lever after downshifting. This system will disengage to a degree to make it skid so that the wheel does not produce that annoying bounce. The main advantage of this device is this in itself; now, you will be able to reduce gears on your neoclassical motorcycle while operating the rear brake and even the front, obtaining stable braking without any fright.

The following are the advantages of a slipper clutch:

  • A correctly installed insole clutch improves performance.
  • It can avoid the catastrophic rear-wheel lockout in the event of engine stalling or transmission failure.
  • It also reduces suspension operation by absorbing the engine’s braking force and thus has less force to handle bends.
  • The rider does not need to focus on the gripping action, which allows him to focus on other things such as posture, braking, etc. When taking a curve.

Disadvantages of the Slipper Clutch

There are practically no downsides to a slipper clutch, but in theory, there are some downsides, such as:

  • It is mechanically complex. Some slip clutches are really complicated to install and operate (not many).
  • It’s expensive (not for the savings it generates by reducing transmission wear, reducing suspension movement, and increasing driver safety).
  • The slipper clutch cannot give desired results if it is not adjusted according to requirements.

How Does A Clutch Slipper Work?

There are two pieces of clutch head-on clutch slippers. The two-piece clutch head is easily extended once torque forces the oblique portion of the chair onto the pressure plate. This easily creates a gap between the clutch plates. Engine brake-force increases rear torque to the rear wheel.

The knurled part of the two-piece clutch head separates from the pressure plate portion of the head. This, in turn, will drive the pressure plate. This movement creates a space between the two clutch discs. After that, the rear torsional force of the rear wheel will decrease.

If you are using a normal clutch, you will feel the engine’s braking force is transmitted to the rear wheel through the chain drive. This causes the rear wheel to jump, jerk, or lose traction.

Therefore, the slipper clutch is designed first to obtain greater control over the rear wheel, especially when braking hard. This clutch will be useful, especially when using large displacement bikes. Larger displacement bikes, of course, have more engine braking power. This tremendous braking force can cause the driver to lose control of his motorcycle.

The good thing about a slipper clutch is that it disengages when it encounters a higher level of rear torque. Then this torque is transmitted from the motorcycle’s engine. After that, he intervenes again and repeats the cycle until he reaches the neutrality between the engine and the rear wheel force. This specific feature of the slipper clutch helps riders avoid losing rear traction.

Why Does Our Slipper Clutch Fail?

The first thing we need to do before we start replacing the clutch is to examine the old parts to see what could have caused them to fail. If, for example, we find the clutch soaked in oil, we will have to identify said leak before thinking about installing a new clutch. If the blades of a diaphragm clutch show great to wear, it can be caused by several causes such as the collar has not been installed correctly, the hydraulic system is not fully retractable, the release cable sticks, the self-regulatory is badly adjusted or defective, or the most common of all evils and the worst habit we can have; keep your foot depressed at all times on the clutch pedal. If, on the contrary, we observe that the diaphragm blades are used unevenly, it means that the clutch was deformed when it was installed because a uniform tightening of the cover is not carried out on the flywheel.

When Should You Replace Slipper Clutch?

A dry slipper clutch is a type of clutch that uses friction to change gears and is the most common.

When a disc on a dry clutch becomes thin, you will notice it scratches when selecting a gear. If this happens, it means that the disc did not properly fulfill its function of transmitting the power from the gearbox to the driving wheels.

Many clutches also have shock absorbers to try and prevent vibrations from the vehicle. If there is a rattle, it could be the shock absorbers, rather than the clutch wheel itself, that have the fault, but it will still have a negative effect on the clutch.

Wet clutches are those that are bathed in lubricant to ease transitions. Because of this, they tend to last longer than dry clutches.

However, some think that they lose energy to the liquid. A wet clutch can be said to be faulty from the quality of the lubricant. If there are pieces of something in it, it is likely due to a faulty clutch. Similarly, if the fluid smells burning, it is a sign that the clutch is using too hard.

Lack of Acceleration

A clear sign that the clutch needs to be changed is when we discover that when we try to overtake or when we go uphill, we accelerate and the engine revs, but the speed does not rise as it should. Similarly, if the clutch is worn, the revs won’t settle as fast as they should, especially on higher gears. If you have a hydraulic clutch, you may need to make sure there is no air in the hydraulic system. If there is air in the system, it can cause problems when changing gears. Empty the system or, if you are not comfortable, ask your mechanic to do it for you.

Clutch Slippage

One of the most obvious signs that it’s time to change your clutch occurs when you change gears. The slipping of the clutch will cause rough switching between the gears. This may cause screeching noise and difficulty in shifting from one gear to the other, even when the RPM is optimum for you to change the gear.

You can easily understand what causes the slipping of the clutch, but in some cases, it is really hard to determine. Slipping of clutch often causes noise but more than that, the feel of the clutch pedal can signal you to fix or replace the clutch.

There are other factors that can tell you if your clutch is faulty, such as:

  • RPM increases without the increase in speed.
  • A loose clutch pedal that gets easily depressed.
  • The accelerator pedal stops working as it were before.
  • If this is not the case or if you feel a particular sensitivity in the clutch pedal, you have probably worked too hard.
  • If you are driving on the highway, you may not notice the clutch much. It will be more apparent when driving in areas where equipment needs to be changed a lot. From a physical point of view, the unusually short path of the clutch pedal indicates that the disc is starting to wear out.

We can do a test to verify the degree of clutch wear. However, although it is relatively simple, it should not be done frequently, as the control itself contributes to shortening the life of the component. We must have the vehicle engine running and the parking brake activated. Don’t do this near the place where the vehicle can damage it if it is thrown forward. It should not be launched, but prevention is better than cure.

Once you’ve started the engine and the gear in the third position, slowly lift your foot off the clutch and press the accelerator. This is known as getting the bite point, just as you would when starting in first gear.

If the vehicle is in third gear, the vehicle should stop. However, if the vehicle takes a while to come to a stop, it probably has a worn clutch.

The longer the vehicle takes to stop, the more worn the clutch is. Changing the clutch is not an easy task, so talk to a professional or seek help from someone who knows what they are doing. It can be a bit expensive, but a bad or badly worn clutch can lead to an engine failure that increases the chances of an accident, especially at high speeds.

Clutch Slip Diagnosis:

A slip clutch not only robs the car of its performance, but it can also leave you stranded if any part of the machine fails completely. But replacing the clutch is a difficult and expensive repair, requiring removal of the transmission to access internal components. You should diagnose the problem causing the slip before making any fixes. Since different parts of the clutch system exhibit unique symptoms and performance issues when malfunctioning, diagnosis can be made through a few simple test drives.

  • Step 1: Park your car on a flat surface with plenty of free space in front and behind to allow a safe diagnosis. A long driveway or empty parking lot is ideal.
  • Step2: Start the engine with the gear lever in “neutral.” Press down on the clutch pedal several times, noting any inconsistencies in pedal pressure. Incompatible pressure can indicate a faulty hydraulic clutch system, which can lead to improper clutch engagement while driving. If you feel inconsistent pedal pressure, inspect the clutch master and slave cylinders for signs of fluid leaks. If there are no leaks, try flushing and replacing the fluid; air bubbles in the system can also lead to hydraulic problems.
  • Step 3: Set the parking brake. Press down on the clutch pedal and move the gear lever into the highest gear setting. Slowly release the clutch pedal while watching the number of revolutions the engine makes. A severely slipping clutch will allow the engine to remain running when the pedal is fully released. If the clutch slips only moderately, the engine RPM will drop when the pedal is fully released. A healthy clutch will catch and stop the engine before the pedal is released all the way.
  • Step 4: Release the parking brake and drive from a stop as you would in a normal driving situation, in first gear. If the clutch slips, the engine will over-rev when you release the pedal and increase the throttle. Also, note that the presence of an active clutch causes the vehicle to sporadically jerk forward when the pedal is released. Clutch chatter can be caused by numerous malfunctions, including excessive heat generated by friction that can lead to a warped flywheel or disc clutch.
  • Step 5: Find a long, empty road to test the clutch on in driving situations. While driving, it shifts from top gear to low gear, with the engine running at approximately 1,500 rpm. A slip clutch will allow the engine to accelerate quickly, while the vehicle speed remains the same. With a healthy clutch, the engine will slowly accelerate with vehicle speed.

Be aware of any burning odours after normal driving. When a clutch slips, the friction generated continuously burns the clutch disc material, creating a strong odor similar to burnt plastic. If there is an odour in the cab, stop the vehicle and open the hood after driving. Since the clutch connects to the rear of the engine, the smell will be much stronger in the engine compartment.

Also Read: History of Cars – Evolution of Features, Technology, & Brilliance

Caution When Using Slipper Clutch

The slipper clutch is designed to slip partially when the tires try to drive the engine faster than it would have done during deceleration. Once the clutch begins to slip, the problem will only get worse as more clutch plates will wear out. Replace the slipper clutch as soon as possible to ensure optimum drivability of your vehicle.

Slipper Clutch… Blessed Clutch

One of the most effective and used mechanical systems in competition motorcycling is the anti-skid clutch (slipper clutch) or also called anti-lock.

The mechanism, located in the same location as the conventional one, consists of a system of ramps at 45º on the clutch drum that allows the sliding of the discs in certain critical driving conditions, and normal operation in the direction of the power transmission of the motor to the rear wheel.

This technical solution allows all to have a full torque transmitting clutch in acceleration, while in sudden retentions when all the mass load passes to the front wheel, and you lose grip on the driving wheel, it partially disengages the transmission, preventing it from the wheel locks up and starts bouncing from one side to the other, an effect that makes it quite annoying to put the bike around the curve. Have you never suffered from it? You haven’t braked hard enough!

Technicality Behind Slipper Clutch

In the acceleration phase, the engine power is transmitted through the clutch and gearbox to the wheel. In this sense the clutch ramps are opposite, and let’s say so, it blocks the system due to a “hook” effect, the clutch discs form a bundle when pressed by the thrust plate and transmit all the engine torque.

When after a long straight, where at the end we find one of those slow curves in which you drop the anchor and start to downshift like crazy, is when you will start to remember the blessed clutch because there is nothing to hold the rear wheel.

At this time, where the adhesion of the rear wheel is very low due to the load transfer to the front axle. The torque that the wheel is capable of transmitting is very low while the resistant torque of the engine, which you force to turn, in relation to the first is high.

This balance of torques, in the opposite direction to normal, that is, from the wheel to the motor, makes the ramps of the system come into operation, overcoming the resistance of the torque regulating spring. These ramps will separate the clutch discs enough to overcome the resistance of this spring until a balance of forces occurs in the system, causing the clutch to slip enough so that it does not lock the rear wheel.

Thank you anti-rebound for facilitating the task that your left hand has not been able to do.

Also Read: What Is A High-Security Registration Plate (HSRP)?

Operation Of The Slip Clutch

Primary Spring:

Presses the set of discs through the pressure plate, replaces the helical springs.

Primary spring operation

  • The origin of the axes corresponds to the free height of the spring, that is when the spring is not compressed
  • Each mm of compression corresponds to one mm of spring height.

How Does The Primary Spring Works?

  • When the clutch is actuated, the primary spring is compressed
  • The spring releases pressure due to the movement of the lever.

Secondary Spring

Presses on the bell, regulate the opening of the clutch and regulate the engine brake.

Secondary Spring Operation

  • The origin of the axes corresponds to the free height of the spring, that is when the spring is not compressed
  • Each mm of compression corresponds to one mm of spring height.

How Does The Secondary Spring Works?

  • The motor brake causes the drum to rotate outwards releasing the discs.
  • The secondary spring is compressed relative to the rest position and generates a contrasting force.

Dock operation

The primary and secondary springs are pre-loaded to generate an initial contrast of force.