BMW M140i / M135i (F20/F21) Carbon Ceramic Brakes Kit
Official Warranty: 1‑year free replacement for quality defects or coating issues under normal (non-track) use.
2012-2019 BMW M140i / M135i (F20/F21) Carbon Ceramic Brake Kits
The F20/F21 M135i and M140i are compact rear-drive-biased hot hatches that often get used as fast road cars with occasional hard mountain-road or track work. Buyers usually want less unsprung mass, stronger repeat-stop confidence, and a cleaner upgrade path around the factory 340mm vs 370mm front-brake split.
- Body style: Hatchback
- Front rotor reference: M140i/M135i: 340mm, 370mm
- Rear rotor reference: M140i/M135i: 345mm
This is an OEM-size replacement kit. The rotors are built to the factory rotor spec and install with the factory caliper when the front caliper is a fixed design and the rotor spec matches. The included pad shape matches the OEM pad shape. If the car uses aftermarket calipers such as Brembo, AP Racing, Alcon, or Wilwood, provide the exact caliper model and StopFlex can supply the matching pad shape. Direct replacement is not confirmed if the front caliper is floating, or if the car already runs a non-OEM-offset rotor and the actual rotor dimensions cannot be supplied.
Why StopFlex CCB
Lightweight
Half the Weight, Sharper Handling. StopFlex carbon-ceramic rotors shed roughly half the mass of equivalent iron discs. This massive drop in unsprung weight instantly transforms your chassis, delivering sharper turn-in response and a significantly more refined road feel.
High-Temp Resistance
Minimal Brake Fade at 900°C (1652°F). While traditional iron rotors severely fade under heavy track loads, our CCB matrix holds a stable 0.30μ friction coefficient even at 900°C (1652°F). You get consistent, predictable stopping power when things get dangerously hot.
Corrosion Resistance
100% Rust-Free Durability. Say goodbye to flash rust after a car wash or heavy rain. The carbon-silicon carbide material is naturally impervious to corrosion, ensuring your brake rotors look completely clean and pristine no matter the weather conditions.
Long Lifespan
250,000+ km (155,000+ mi) Lifespan. Iron rotors typically require replacement around 100,000 km (62,000 mi). In normal street driving conditions, a StopFlex CCB rotor can easily last 250,000 to 300,000 km (155,000 to 186,000 mi), effectively outlasting the vehicle itself.
Ultra-Low Dust
Ultra-Low Visible Brake Dust. Heavy black dust destroying your wheel finish is a thing of the past. When paired with our matched StopFlex pads, these rotors generate virtually zero visible brake dust, keeping your premium wheels spotless for much longer.
Premium Visual Finish
Premium Mirror-Like Finish. StopFlex utilizes a patented ceramic formula that cures with a distinct crackle pattern. The surface is machined dead-smooth for high reflectivity, providing a premium aesthetic behind open wheels under the right lighting.
High Normal-Temp Friction
Strong Initial Bite (0.40μ+). With matched StopFlex pads, normal-temperature friction can exceed 0.40μ for a firmer pedal feel and strong initial bite.
Long-Fiber Construction
Continuous Long-Fiber Strength. StopFlex utilizes a continuous long-fiber 3D matrix. This structure is significantly stronger and offers higher thermal conductivity than standard chopped-fiber OEM CCM discs.
Cold First-Stop Confidence
Reliable Cold-Bite at -20°C (-4°F). Coated street rotors still deliver normal first-stop braking at -20°C (-4°F). Uncoated motorsport rotors are the exception.
Important heat note
Carbon ceramic does not shed heat as fast as steel. Long hard driving can heat-soak the rest of the brake system, including fluid, seals, and nearby parts. Unless the car already has strong brake cooling, or you plan to upgrade brake cooling, prolonged aggressive driving is not recommended.
Rotor options
Street Spec
Ceramic coating + cross-drilled face + large cooling channels.
340mm front is the sensible choice for mainly road-driven M135i/M140i builds that want lighter feel and easier wheel fitment.
Track-Day Spec
Ceramic coating + blank face + honeycomb cooling channels.
370mm front is the better all-rounder for mixed street and repeated hard-use driving on this chassis.
Motorsport Spec
No coating + blank face + honeycomb cooling channels. Not for normal street use.
370mm front with proper cooling support is the stronger option for sustained lapping or very demanding use.
Pads
| Item | Details |
|---|---|
| Pad shape | The included StopFlex pad shape matches the OEM pad shape used by the retained caliper. |
| Aftermarket calipers | Provide the exact caliper model and StopFlex can supply the matching pad shape. |
| Pad details | For compound details and pad-specific parameters, see the StopFlex Ceramic Brake Pad for CCB Rotor product page. |
What’s included
| Item | Included |
|---|---|
| CCB rotors | Full-car set |
| CCB brake pads | Full-car set |
| 7075 aluminum floating rotor hats | Full-car set |
| Stainless floating hardware | Full-car set |
| Order scope | Default listing includes front set + rear set. Front-only or rear-only can be ordered separately. |
FAQ
Will a StopFlex carbon ceramic brake kit for my BMW M140i or M135i F20/F21 work with the factory calipers, or do I need different calipers?
It depends on whether your car has the 340mm or 370mm front setup and which factory-style caliper/bracket arrangement is on the car. On this platform, owners regularly run into 340mm vs 370mm compatibility confusion, so caliper and bracket details should be confirmed before ordering.
Which StopFlex rotor size should I choose for my F20/F21 M140i or M135i: 340mm or 370mm front?
Choose 340mm if your car is a mainly street-driven hatch and you want the closest match to the smaller factory setup. Choose 370mm if you do repeated fast-road or track-style braking and want more thermal headroom on the front axle.
Is a StopFlex carbon ceramic kit on an F20/F21 M140i or M135i still a good daily-driver setup in cold first-stop use?
Yes, if your priority is a road-biased setup rather than a pure track-focused one. Most buyers for this chassis should order with daily use in mind, because these cars are commonly used as year-round performance hatchbacks rather than dedicated track cars.
If I use my BMW M140i or M135i F20/F21 hard, will a StopFlex carbon ceramic brake kit control heat on its own, or do I still need cooling help?
For short aggressive road use, the upgrade gives you more margin than the smaller iron setup. For repeated hard laps or long downhill work, cooling airflow and the rest of the brake package still matter, especially on cars driven beyond normal fast-road use.
Need fitment confirmation?
Send the exact vehicle details and current brake setup before ordering.
More Contact Information
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