What is the Purpose of a Slipper Clutch?
A slipper clutch, or back-torque limiter, is a specialized clutch with an integrated freewheel mechanism. It was developed for racing motorcycles to mitigate the effects of engine braking when riders downshift too quickly.
Earlier, slipper clutches were used only in race bikes. However, nowadays, slipper clutches come standard in all types of motorcycles – from performance machines, like the Ducati Panigale, to beginner bikes, like the Kawasaki Ninja 300, and even sport-tourers and cruisers.
What is the purpose of a slipper clutch?
The main purpose of a slipper clutch in a motorcycle is to avoid the dangerous effects of tire hopping or skidding due to engine braking during deceleration and downshifting by allowing the rear wheel to spin freely instead of abruptly going much slower than the front wheel. Slipper clutches are designed to work during the braking phase, i.e. when the motor isn’t providing power.
In simpler terms, the main purpose of a slipper clutch is to prevent the engine from over-reving as well as preventing the rear wheel from skidding or hopping due to engine lockup, especially under hard engine braking caused by aggressive downshifts. That also keeps the rear wheel on the ground during hard engine braking, ensuring the suspension works properly.
At the racetrack, a slipper clutch is helpful because downshifts are usually performed under hard braking. The high RPMs can suddenly make the rear wheel’s rotation much slower than the actual road speed, causing an “engine braking” effect, taxing the rear tire and suspension. It can also create a static load pressing the rear tire against the pavement. As a result, your motorbike's rear-wheel can hop, leading to full-on skid and even crashes.
On the streets, a slipper clutch comes into play in the following situations:
- Accidental downshifts
- A sloppy shift on a wet or slippery surface
Most folks don't make these kinds of mistakes, but if they do, a slipper could save them from a potential accident.
How does a slipper clutch work?
The most common type of slipper clutch has ramps assembled into the inner basket and the pressure plate. When the rear wheel begins driving the engine under deceleration, the ramps are forced together, and they ride up one other. It pushes the pressure plate away from the clutch pack, reducing the clamping force on the clutch plates, and letting them slip past each other so that the rear wheel turns with less engine drag, slowing it down so that the engine revs don't get pushed through the roof. It's the same action you'd get if you apply a little pressure to the clutch lever. With a slipper clutch it happens automatically so you don't have to put any additional effort or thought into it, which means that no rev-matching or clutch finesse required.
Slipper Clutches available at Motowheels
At Motowheels, you can find a complete range of motorcycle aftermarket components and accessories for a variety of bikes including Ducati, KTM, Aprilia, MV Agusta, and more.
Check out two of our popular Slipper Clutches:
1.) STM EVO-GP SLIPPER CLUTCH KIT INCLUDING BILLET CRANKCASE COVER. The STM clutch components are made of high-quality materials, like anodized alloy and titanium, making it lighter than an OEM clutch. The STM clutch improves the overall performance of your vehicle, extends the life of the engine and is adjustable for engine braking and clutch slippage. Plus, it converts the stock wet clutch to dry for easy servicing and that amazing dry-clutch sound.
Shop now> STM SLIPPER CLUTCH KIT
2.) EVR CTS SLIPPER CLUTCH COMPLETE WITH 48T SINTERED PLATES AND BASKET. EVR’s CTS slipper clutch improves stability and lap time on the track by eliminating rear wheel chatter on the corner. It requires no maintenance and has no parts (like spider springs) that wear out regularly! EVR slipper clutches utilize a patented technology that significantly improves operation and clutch life when compared to other slipper clutches on the market.
Shop now> EVR CTS SLIPPER CLUTCH
At Motowheels, you will find the latest highest quality motorcycle parts and accessories at affordable prices. Ready to add race-ready slipper-clutch performance for your motorcycle?