The facts.
| Brand | STM |
|---|---|
| Part number | FBM-S021 |
| Type | Slipper clutch (anti-hopping clutch) |
| Fitment | BMW S1000RR K67 (2019–2026) |
| Anti-hopping mechanism | Patented ball-ramp system |
| Pressure plate design | Diaphragm spring |
| Weight saving | Approx. 0.7–0.8 kg reduction in rotating mass |
| Primary material | Machined aluminium |
| Intended use | Road and track (Superbike / sport riding) |
DescriptionThe whole story▼
STM's slipper clutch for the BMW S1000RR K67 is the product of decades of Italian racing engineering, combining a beautifully machined billet aluminium basket with patented ball-ramp anti-hopping geometry that has proven itself at the highest levels of Superbike competition. For riders who demand total rear-wheel composure under hard braking and aggressive downshifts, this is the definitive upgrade.
Key Features
- Patented ball-ramp mechanism controls the anti-hopping function with exceptional precision, delivering stability at high engine speeds that conventional clutches simply cannot match.
- Eliminates rear-wheel hop and reduces the trigger impulse of a highside, adding a meaningful safety margin during track sessions and spirited road use alike.
- Controlled rear-wheel slide characteristic improves feel and handling when transitioning on the throttle mid-corner.
- Superior clutch-closure control in bends prevents the motorcycle from tucking under load, keeping the chassis neutral through the arc.
- Diaphragm spring replaces the conventional pressure plate, removing wobble at the point of release for a more progressive, tactile lever feel.
- Weight saving of approximately 0.7–0.8 kg through a significant reduction in rotating mass — a tangible improvement in throttle response and overall performance.
Design, Finish and Heritage
STM has been manufacturing racing clutches in Italy since the 1990s, supplying factory World Superbike and Moto2 teams with components that meet the demands of professional competition. Every element of this clutch reflects that lineage: the precision-machined aluminium components carry the fine tolerances you would expect from a race-developed part, and the overall assembly is engineered to perform consistently lap after lap without the degradation that affects standard OEM units under repeated thermal and mechanical stress.
The ball-ramp anti-hopping system is a genuine STM patent — not an adaptation of a third-party design — which means the progressive ramp profile, the spring preload and the engagement point have all been developed and refined in-house specifically for high-power Superbike applications. On the S1000RR K67, whose inline-four produces aggressive engine braking, the difference in rear-wheel stability and rider confidence is immediately apparent.
Performance on Road and Track
Under hard braking into a late apex, the slipper mechanism allows the clutch to partially disengage as the rear wheel decelerates faster than the engine, smoothing the transition and keeping the tyre loaded rather than bouncing. In the corner itself, the diaphragm spring ensures the clutch closes progressively rather than snapping shut, preventing the chassis dive that can unsettle a line. The net result is faster, more consistent lap times and a noticeably more composed ride on challenging public roads.
Fitment and Compatibility
This clutch is designed and manufactured to fit the following motorcycle:
- BMW S1000RR K67 — model years 2019 to 2026
Part number: FBM-S021. Always verify fitment against your VIN and model designation before ordering.
Specifications
| Specification | Detail |
|---|---|
| Brand | STM |
| Part number | FBM-S021 |
| Type | Slipper clutch (anti-hopping clutch) |
| Fitment | BMW S1000RR K67 (2019–2026) |
| Anti-hopping mechanism | Patented ball-ramp system |
| Pressure plate design | Diaphragm spring |
| Weight saving | Approx. 0.7–0.8 kg reduction in rotating mass |
| Primary material | Machined aluminium |
| Intended use | Road and track (Superbike / sport riding) |
FitmentWhich bikes this fits▼
- BMW S1000RR K67 (2019–2026)
Questions, one topic at a time.
Get the real shipping cost for this item to your address — the same rates as checkout.
Choose a destination and hit Estimate — we fetch the live rates for this item.
We’re based in Germany. Standard delivery goes by DHL and national postal services and takes about 2–5 days within Germany, 1–2 weeks within the EU and 2–6 weeks outside the EU. Need it sooner? Express delivery reaches most of the world within a few days — just choose it at checkout where available.
Your exact shipping cost is calculated by destination and weight and shown at checkout before you pay — no hidden fees. Express delivery is selectable at checkout where available.
Yes, we ship to over 130 countries. Prices, taxes and delivery times for your destination are calculated automatically at checkout.
Within the EU, no — our prices already include all duties and EU VAT. For deliveries outside the EU (e.g. Switzerland, the UK or the USA), your order may be subject to import duties and taxes set by your country. These are collected by the carrier when your parcel arrives, aren’t included in our prices, and are outside our control.
As soon as your parcel ships we email you a tracking link, so you can follow it all the way to your door.
On out-of-stock items you can request a delivery time or leave your email to be notified the moment it returns — just use the notification box on the product.
You have the right to cancel within 14 days of receiving your order. Register your return by email first; once it’s approved you have a further 14 days to send the goods back. Items should be unused and in their original packaging.
Register your return by email with your order number before sending anything back, and we’ll send you the return instructions. Please note: returns that aren’t registered in advance can’t be accepted.
The quickest way is to place a new order for the size you need and register a return for the original by email — just let us know it’s an exchange.
We’re sorry — that shouldn’t happen. Contact us with your order number and a photo as soon as you can, and we’ll arrange a replacement or refund right away. Faulty goods are always covered by your statutory warranty.
Refunds go back to your original payment method, usually within 3–5 working days of your return reaching our warehouse.
PayPal, all major credit and debit cards (Visa, Mastercard, American Express), Klarna (pay later and instalments), Apple Pay, Google Pay and more — all processed securely via PayPal and Mollie.
Yes. Choose Klarna at checkout to split your purchase into flexible monthly installments.
Your payment is taken when you place your order. If you choose Klarna, you pay later according to Klarna’s terms.
Every payment runs over an SSL-encrypted connection through certified providers. We never see or store your full card details.
If your order hasn’t shipped yet, contact us as soon as possible and we’ll do our best to change or cancel it.
No — you can check out as a guest. An account simply lets you track orders and reorder faster.
For customers in the EU, prices are shown including your country’s local VAT. For customers outside the EU, prices are shown without VAT — instead, your country’s import taxes and duties may apply on delivery (see the customs question).
Yes. Your invoice is attached to your order confirmation email and is also available in your account.
Yes. We’re an authorised dealer, so every product is 100% original and comes with the full manufacturer warranty.
Yes. Everything we sell is genuine and comes with the manufacturer’s warranty, on top of your statutory rights. Keep your invoice as proof of purchase and contact us if you ever need to make a claim — we’ll help you through it.
Our team is happy to help. Use the contact button below and we’ll personally help you choose the right gear or part.
Measure your head circumference about one centimetre above your eyebrows and compare it with the size chart on this page. Between sizes? Choose the smaller one — the padding beds in with use.
Yes — it’s tested and approved to the current ECE 22.06 standard and road-legal across the EU.
Most of our touring and sport helmets are Pinlock-ready and many include the insert. Check the ‘What’s in the box’ section on this page for this model.
Yes — the cheek pads are channelled so the arms of your glasses slide in comfortably.
Take out the washable lining and hand-wash it in lukewarm water. Clean the shell and visor with a soft cloth and water only — never solvents.
Our team will personally help you choose the right gear or part — around 24h for a reply.