2019-2026+ BMW M340i / M340d (G20/G21) Carbon Ceramic Brake Rotors
Official Warranty: 1‑year free replacement for quality defects or coating issues under normal (non-track) use.
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Will This Fit My Car?
Direct Replacement CCB Discs (Retain Factory Calipers) for the 2019-2026+ BMW M340i / M340d (G20/G21). Factory rotor specifications and the smallest wheel that clears each trim:
| Trim | Front Rotor (Factory) | Rear Rotor (Factory) | Min. Wheel Size |
|---|---|---|---|
| M340i/M340d | 348mm, 374mm | 345mm | 19" |
Keep Your Factory Calipers?
Yes — if your front factory calipers are fixed 4-piston or more. The rear axle has no restriction. Cars with 1- or 2-piston floating front calipers should use the Full Upgrade kit (calipers + discs) instead. Discs are built to the factory rotor specs shown above; if you run aftermarket calipers (Brembo, AP Racing, Alcon, Wilwood), we simply confirm the caliper model, pad shape, and rotor dimensions before production.
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 |
| 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
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 carbon-ceramic rotor weighs roughly half of the equivalent iron disc. Less rotating, unsprung mass lets the suspension follow broken pavement more cleanly and makes steering response noticeably sharper.
High-Temperature Stability
The carbon-silicon-carbide friction matrix keeps working at temperatures that push iron rotors into heavy fade, so the tenth hard stop feels like the first — same pedal travel, same bite point.
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, one StopFlex CCB rotor set is engineered to outlast several sets of iron replacement rotors, recovering part of the up-front cost.
Low Visible Dust
Matched with StopFlex pads, the system sheds a fraction of the dust an iron rotor and pad combination throws. Wheels stay clean for weeks of driving instead of days.
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.
Continuous Fiber Construction
StopFlex discs are built with long continuous carbon fiber instead of chopped short fiber. Continuous strands carry load across the whole rotor body, raising strength and thermal durability under heat cycles.
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.
Winter & Cold-Weather Braking
Winter question, straight answer: untuned ceramic discs bite less when cold. StopFlex optimized the pad compound and the rotor's ceramic coating for cold operation, so cold-start braking in winter feels very close to warm-weather braking. Extra following distance on freezing first stops is still smart; severe-winter daily cars should run Street Spec.
Choose Your Rotor: Street, Track-Day, or Motorsport
Street Spec
Ceramic coating, cross-drilled face, and large cooling channels.
Best for daily driving and premium street builds that need clean cold bite, low dust, corrosion-free appearance, and long service life.
Track-Day Spec
Ceramic coating, blank face, and honeycomb cooling channels.
Best for fast-road and track-day use where repeated braking stability matters more than maximum visual drilling style.
Motorsport Spec
Uncoated blank face with honeycomb cooling channels.
Best for race-focused builds that run competition pads, high-temperature fluid, cooling strategy, and a proper warm-up window. Not the default street choice.
Heat Management Note
Ceramic discs shrug off surface temperatures that would destroy iron, but the rest of the system still heats up: pads, fluid, seals, calipers, and wheels all absorb soak heat during repeated hard stops. For track days, long descents, and sustained hard driving, run brake cooling and high-temperature fluid.
Get Your Fitment Confirmed
Before ordering, tell us the exact vehicle, current rotor sizes, and caliper type. Nothing goes to production until the build is confirmed against your VIN-level configuration.
FAQ
Will this fit my M340i or M340d if I keep the factory calipers?
Yes, this is a direct-replacement kit that reuses your G20/G21 front calipers, provided your front factory caliper is a 4-piston or larger fixed unit. The rear has no piston restriction. It matches the factory front rotor sizes of 348mm or 374mm and the 345mm rear on M340i and M340d. Confirm which front rotor diameter your car left the factory with, since the kit hats and floating hardware are built to that exact size.
How do these carbon-ceramic discs behave on a cold winter morning?
An untuned cold carbon-ceramic disc bites less than cold iron on the first stop — that's normal ceramic physics, not a fault. StopFlex tunes both the pad compound and the disc's ceramic coating for cold starts, so cold-car feel on the G20 now comes very close to summer feel. Leave a little extra following distance on your first couple of stops on the coldest days and the system comes up to normal bite quickly.
Does this work with the electronic parking brake on the G20/G21?
Yes. The rear kit retains your factory rear calipers and their integrated electronic parking brake actuators on the 345mm rear rotor, so EPB and Auto Hold function exactly as they did from the factory. No coding or actuator swap is required.
I've tuned my B58 past 400 horsepower — is the stock front rotor size enough?
The front rotor diameter stays the same as factory (348mm or 374mm depending on your build), but the carbon-ceramic disc raises the thermal ceiling well above the iron rotor it replaces. The matched pad holds a stable friction coefficient of about 0.44 and resists fade to roughly 750 °C, which is where a tuned M340i tends to expose iron brakes on repeated hard stops from highway speed.
More Contact Information
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