2019-2026+ BMW M340i / M340d (G20/G21) Carbon Ceramic Brake Kit
Official Warranty: 1‑year free replacement for quality defects or coating issues under normal (non-track) use.
2019-2026+ BMW M340i / M340d (G20/G21) Carbon Ceramic Brake Kit — OEM-Size Replacement
The G20/G21 M340i and M340d use large OEM M Sport brake hardware, but repeated high-speed stops, heavy street use, and open-wheel brake dust can still make the factory iron setup the limiting part of the car. This StopFlex OEM-size carbon-ceramic kit replaces the listed 348mm or 374mm front rotors and 345mm rear rotors with carbon-ceramic discs, matched pads, hats, and floating hardware built around the original caliper positions. The payoff is higher heat stability, lower rotor mass at each corner, and far less visible dust while keeping the brake package tied to the exact BMW rotor size on the car.
- Built only for 2019-2026+ BMW M340i / M340d G20 sedan and G21 touring fitments using the listed 348mm or 374mm front rotor and 345mm rear rotor references.
- Works with the factory-style front fixed-caliper M Sport layout and rear 345mm brake package; ordering must match the car’s actual front rotor diameter.
- Carbon-ceramic rotors reduce the dust and heat load that M340i and M340d owners notice during fast road driving, mountain descents, and repeated highway-speed braking.
Fitment Hard Lines
| Field | Specification |
|---|---|
| Vehicle | BMW M340i / M340d (G20/G21) |
| Model years | 2019-2026+ |
| Front rotor reference | M340i/M340d: 348mm, 374mm |
| Rear rotor reference | M340i/M340d: 345mm |
| Page type | OEM-size carbon ceramic replacement |
| Minimum wheel size | 18" (for the 340 mm rotor) |
For OEM replacement orders, StopFlex builds around the factory rotor specification shown for this vehicle. Front floating-caliper setups require manual review before production. If the car uses aftermarket calipers such as Brembo, AP Racing, Alcon, or Wilwood, the order can still be built, but the exact caliper model, pad shape, and rotor dimensions must be confirmed before production.
This setup uses a 340 mm rotor, so the minimum wheel size is 18". Wheels under 18" will not clear the caliper and rotor, and spoke profile and offset affect clearance too — confirm your exact wheels before ordering.
Why StopFlex CCB
Lower Unsprung Mass
StopFlex carbon-ceramic rotors are engineered to reduce rotor mass versus comparable iron discs, helping the suspension react cleaner and the steering feel more precise.
High-Temperature Stability
The carbon-silicon-carbide matrix is built for stable braking behavior at temperatures that can push iron rotors into heavy fade.
Rust-Free Rotor Surface
Carbon ceramic does not form orange flash rust after rain, washing, or storage, keeping the visible rotor face cleaner behind open wheels.
Long Street-Service Potential
In normal road use with matched pads and proper bedding, StopFlex CCB rotors are designed for far longer service life than typical iron replacement rotors.
Low Visible Dust
When paired with matched StopFlex pads, the system produces very low visible brake dust compared with conventional iron rotor and pad combinations.
Premium Ceramic-Glaze Appearance
StopFlex's proprietary coating creates a bright, high-end ceramic-glaze finish with subtle glaze texture and a more premium visual character behind open wheels.
Street-Usable Cold Bite
Street Spec and Track-Day Spec rotors are designed for normal first-stop road use, including cold-weather operation. Motorsport Spec is the competition-focused exception.
Continuous Fiber Reinforcement
Long-fiber carbon ceramic construction improves structural strength and thermal durability versus chopped-fiber approaches.
Custom Rotor Hat Color
Every StopFlex OEM replacement order can be built with a custom rotor hat color, giving the carbon ceramic rotor package a cleaner match with the wheel, body color, and overall build style.
Heat Management Note
Carbon ceramic rotors tolerate extreme surface temperature, but they do not remove every heat-management requirement. During repeated hard stops, heat can still soak 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.
Street / Track-Day / Motorsport Rotor Options
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.
Package Scope
| Item | Details |
|---|---|
| CCB rotors | Full-car set by default |
| CCB brake pads | Matched for StopFlex carbon ceramic rotors |
| 7075 aluminum floating rotor hats | Vehicle-specific fitment |
| Stainless floating hardware | Full-car hardware set |
| Rotor hat color | Custom rotor hat colors are available for every OEM replacement order. |
| Order scope | Default listing is full-car set. Front-only or rear-only orders can be arranged after confirmation. |
FAQ
Will this kit fit every 2019-2026+ M340i or M340d?
No. This page is limited to G20/G21 M340i and M340d cars with the exact OEM-size brake setup listed here: 348mm or 374mm front rotors and 345mm rear rotors. Confirm the front rotor diameter before ordering because BMW used more than one front brake size in this trim family.
Does the rear electronic parking brake and Auto Hold still work?
Yes, the kit keeps the rear brake architecture in the OEM position and is supplied as rotors, pads, hats, and floating hardware for the 345mm rear setup. The factory EPB motor, parking-brake function, and Auto Hold operation remain tied to the original rear caliper system.
Why change from the factory iron rotors on a G20/G21 M340i or M340d?
The factory iron rotors are heavy wear items that create dark dust and store heat during repeated braking. Carbon-ceramic rotors give this chassis better thermal stability, lower rotating and unsprung mass, and cleaner wheels while retaining OEM-size fitment.
What should I confirm before placing the order?
Confirm the vehicle is a G20 or G21 M340i/M340d, measure or verify whether the front rotor is 348mm or 374mm, and check wheel barrel clearance against the brake package on the car. If the car has non-original wheels, spacers, or a prior brake conversion, verify fitment before ordering.
Need Fitment Confirmation?
Send the exact vehicle details, current rotor sizes, and caliper type before ordering.
More Contact Information
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