2017-2026+ Audi RS4 / S4 (B9) Carbon Ceramic Brake Rotors — Direct Replacement
Official Warranty: We offer a 1-year free replacement for quality defects or coating issues under normal (non-track) use. Please note that provided specs apply strictly to brake hats and brackets; wheel fitment data is for general reference only. Wheel clearance issues are excluded from warranty coverage and data accuracy claims. If additional clearance is needed, wheel spacers must be added at the customer's discretion.
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Will This Fit My Car?
Direct Replacement CCB Discs (Retain Factory Calipers) for the 2017-2026+ Audi RS4 / S4 (B9). Factory rotor specifications and the smallest wheel that clears each trim:
| Trim | Front Rotor (Factory) | Rear Rotor (Factory) | Min. Wheel Size |
|---|---|---|---|
| RS4 | 375mm, 400mm (CCB) | 330mm | 20" |
| S4 | 350mm | 330mm | 18" |
Keep Your Factory Calipers?
Keep the factory calipers when the front axle uses fixed 4-piston-or-larger calipers; the rear axle has no piston-count restriction. Front 1- or 2-piston floating calipers require a Full Upgrade kit. Aftermarket-caliper applications are not assumed to fit: StopFlex reviews the caliper model, pad shape, rotor dimensions and offset before approving the build.
Spoke profile and offset also affect clearance — confirm your exact wheels before ordering.
What's in the Box
| Item | Details |
|---|---|
| Product type | Direct Replacement CCB Discs (Retain Factory Calipers) |
| CCB rotors | Full-car set by default, built to the factory rotor specification |
| Rotor construction | Short-Fiber Street Spec (lower price, street-only) or Long-Fiber Street / Track-Day / Motorsport Spec — chosen at order confirmation |
| CCB brake pads | Matched ceramic-compatible compound for StopFlex carbon ceramic rotors |
| 7075 aluminum floating rotor hats | Vehicle-specific fitment; custom rotor hat colors available for every Direct Replacement order. |
| Stainless floating hardware | Full-car hardware set |
| Order scope | Default listing is full-car set. Front-only or rear-only orders can be arranged after confirmation. |
Why Carbon Ceramic — and Why StopFlex
Premium Ceramic-Glaze Finish
StopFlex's proprietary coating gives the disc a bright ceramic-glaze surface with subtle texture — the factory carbon-ceramic look, clearly visible through open wheel designs.
Short-Fiber or Long-Fiber — Your Call
Every StopFlex disc is true carbon-ceramic. Short-Fiber Street Spec uses a simpler chopped-fiber process for a lower price and street-only duty; the Long-Fiber line uses continuous carbon strands that carry load across the whole rotor for higher strength and thermal durability — the pick for track and race heat.
Bespoke Per-Vehicle Engineering
Every order is machined to the confirmed vehicle and trim. Brackets, hat offsets, and pad shapes are built for that exact car — never pulled from a one-size-fits-all catalog.
CCB-Specific Pad Compound
A low-metallic resin pad compound reinforced with steel, copper, and aramid fiber, made for ceramic discs: stable to about 750 °C, roughly 0.44 average friction, strong fade resistance, low rotor wear.
Lower Unsprung Mass
A like-size carbon-ceramic rotor can be materially lighter than an iron disc; the exact saving depends on rotor dimensions. Lower rotating, unsprung mass can reduce the load the suspension has to control.
High-Temperature Stability
The carbon-silicon-carbide friction material is selected for high-temperature stability and fade resistance. Overall pedal feel still depends on pad condition, fluid, caliper stiffness, cooling and operating temperature.
Rust-Free Rotor Surface
Ceramic discs cannot flash-rust. After rain, a wash, or weeks of parking, the rotor face behind your open-spoke wheels stays clean — no orange ring on a freshly detailed car.
Long Street-Service Life
In normal road use with matched pads and correct bedding, carbon-ceramic friction surfaces are designed for low wear. Actual service life depends on mileage, contamination, pad choice, heat cycles and driving use.
Low Visible Dust
Matched StopFlex pads are selected for low visible dust on the ceramic friction surface. Actual wheel dust still varies with pad choice, traffic, temperature, bedding and driving intensity.
Winter & Cold-Weather Braking
Winter use is possible, but cold-start behavior should be treated honestly: ceramic friction can have less initial bite before temperature builds. StopFlex tunes the matched pad/coating combination for cold response; keep extra distance on the coldest first stops and select a Street Spec for severe climates.
Choose Your Rotor: Short-Fiber Street to Long-Fiber Motorsport
Left to right is ascending duty. Short-Fiber Street Spec keeps carbon-ceramic benefits at a lower price for street use only; the Long-Fiber Street, Track-Day, and Motorsport specs add continuous-fiber strength and thermal durability for everything from daily premium builds to race weekends.
Short-Fiber Street Spec
Chopped short-fiber carbon-ceramic body, ceramic coating, cross-drilled face.
Choose this for street-only use when purchase price matters most. It keeps the carbon-ceramic friction surface and coated finish, but it is not specified for track sessions.
Long-Fiber Street Spec
Continuous long-fiber body, ceramic coating, cross-drilled face, large cooling channels.
Choose this for daily and fast-road use when you want the long-fiber construction without moving to a track-focused face and cooling specification.
Long-Fiber Track-Day Spec
Continuous long-fiber body, ceramic coating, blank face, honeycomb cooling channels.
Choose this for repeated fast-road or track-day braking where thermal duty matters more than the drilled street appearance. High-temperature fluid and appropriate cooling still matter.
Long-Fiber Motorsport Spec
Continuous long-fiber body, uncoated blank face, honeycomb cooling channels.
Choose this for competition-focused use with the corresponding pad, fluid, cooling and warm-up strategy. It is not the default recommendation for a street-driven car.
Heat Management Note
Carbon ceramic rotors tolerate extreme surface temperature, but they do not remove every heat-management requirement. During repeated hard stops, heat still soaks into pads, fluid, seals, calipers, wheels, and nearby components. For long track sessions, mountain descents, or sustained aggressive driving, brake cooling and high-temperature fluid are still recommended.
Get Your Fitment Confirmed
Share your year, model, trim, wheel size, current rotor dimensions, and caliper type. The build is checked against those supplied details before production; VIN/build information may be requested for ambiguous configurations.
FAQ
Which 2017-2026+ Audi B9 RS4 or S4 brake configuration does this direct-replacement set cover?
This listing is limited to the supplied B9 RS4/S4 configurations. RS4 front rotors are 375mm or 400mm (CCB), with 330mm rear rotors; S4 uses 350mm front and 330mm rear rotors. Confirm the rotor size on your vehicle before ordering. Front factory calipers must be fixed 4-piston or larger; rear-caliper eligibility is unrestricted.
Do I keep the factory calipers on my B9 RS4 or S4?
Yes. This is a Direct Replacement CCB disc configuration that retains the factory calipers rather than converting the car to a different caliper system. The supplied package includes StopFlex CCB rotors, matched pads, vehicle-specific rotor hats, and floating hardware. On the front axle, your existing factory calipers must be fixed 4-piston units or larger.
Which StopFlex rotor spec should I choose for an RS4 or S4 that sees street or track use?
Choose Short-Fiber Street Spec only for lower-cost street use. Long-Fiber Street is the step up for more demanding road driving, while Long-Fiber Track-Day and Motorsport are intended for progressively higher heat and duty requirements. Select the rotor spec around how the car is actually used, not simply the largest listed RS4 or S4 rotor diameter.
How do these carbon-ceramic discs behave in winter or on the first cold stops?
An untuned cold carbon-ceramic disc can have less initial bite than cold iron. StopFlex specifies a matched carbon-ceramic pad compound and disc coating to reduce that cold-start gap, but the coldest first stops still deserve extra margin. Do not expect identical initial response across summer temperatures, winter temperatures, and every driving condition.
More Contact Information
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