The facts.
| Brand | STM |
|---|---|
| Part Number | FKW-S050 |
| Type | Slipper / anti-hopping clutch |
| Fitment | Kawasaki ZX-6R / 636 / RR (2007–2018) |
| Weight Saving | approx. 0.7–0.8 kg (rotating mass reduction) |
| Mechanism | Patented ball-ramp anti-hopping system |
| Spring Type | Diaphragm spring |
DescriptionThe whole story▼
Engineered for riders who demand complete confidence through every downshift, the STM slipper clutch for the Kawasaki ZX-6R, 636 and RR (2007-2018) transforms clutch feel from a source of tension into a genuine advantage. Whether you are threading a fast chicane or braking deep into a hairpin, this unit keeps the rear wheel planted and the bike obediently on line — lap after lap, without fatigue.
Key Features
- Eliminates engine over-rev on aggressive downshifts, delivering a smooth, controlled deceleration that keeps your entry line intact
- Reduces rear-wheel hop to improve traction and stability under trail braking — less drama, more confidence in the saddle
- Lowers the trigger impulse of a potential highside, significantly reducing risk at high speed and giving the rider a genuine safety margin
- Allows controlled rear-wheel slides for a more progressive, predictable handling balance during spirited riding
- Improved clutch-closure control through corners prevents the front end from tucking — a critical benefit when carrying speed mid-turn
- Diaphragm spring design smooths lever release and eliminates pressure-plate judder, reducing hand fatigue on long track sessions or spirited road rides
- Patented ball-ramp mechanism governs the slipper function with precision at high revs, providing consistent, repeatable performance every time
- Saves approximately 0.7–0.8 kg in rotating mass, reducing drivetrain inertia and sharpening throttle response across the entire rev range
All-Day Comfort and Ride Quality
One of the most overlooked benefits of a high-quality slipper clutch is how much more comfortable the riding experience becomes over the course of a full day. The diaphragm spring inside the STM unit requires less lever effort than a standard spring-plate clutch, so your left hand is not fighting the lever at every corner entry. Over a long track day or an extended road run, that reduction in effort adds up to noticeably less arm and hand fatigue — leaving you fresher, sharper and able to ride at your best when it matters most.
The improved clutch-closure feel also gives you a cleaner mental picture of what the rear tyre is doing, removing the guesswork that a chattering or hopping wheel creates. That clarity translates directly into greater confidence on corner entry, which is where lap times and riding enjoyment are truly made.
Patented Ball-Ramp Technology
STM's patented ball-ramp system is the engineering heart of this clutch. Rather than relying on crude friction-based slippage, the ball ramps meter the degree of clutch disengagement in direct proportion to the level of engine braking force being generated. The result is a progressive, linear response that adapts to each downshift situation — aggressive or gentle — without any sudden release or unexpected rear-end behaviour. At race pace, where margin for error is zero, that precision is the difference between a controlled slide and an uncontrolled moment.
Fitment and Compatibility
This STM slipper clutch is a direct-fit replacement for the following models:
- Kawasaki ZX-6R — 2007 to 2018
- Kawasaki ZX-6R 636 — 2007 to 2018
- Kawasaki ZX-6RR — 2007 to 2018
Specifications
| Brand | STM |
|---|---|
| Part Number | FKW-S050 |
| Type | Slipper / anti-hopping clutch |
| Fitment | Kawasaki ZX-6R / 636 / RR (2007–2018) |
| Weight Saving | approx. 0.7–0.8 kg (rotating mass reduction) |
| Mechanism | Patented ball-ramp anti-hopping system |
| Spring Type | Diaphragm spring |
FitmentWhich bikes this fits▼
- Kawasaki ZX-6R / 636 / RR (2007–2018)
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