Formula 1 carbon brake disc showing the rows of cooling holes drilled through the carbon friction ring and the aluminium mounting bell

F1 Brake Discs Explained: Why Carbon Glows at 1,000 Degrees

September 23, 2026

Welcome to the Happy Hour Racing Formula 1 Tech Breakdown - where we take one confusing part of Formula 1 and make it make sense. No engineering degree required.

The Short Version

An F1 brake disc is not metal. It is carbon, built up in layers and baked for months, and it only works properly once it is glowing. The rules give it a size box and then refuse to help the driver in any way, no anti-lock, no power assistance. For 2026 the FIA rewrote that size box, and the brakes on this year's cars are the most changed they have been in two decades.

The Disc Is Not Metal, and It Takes Four Months to Build

Your road car stops on cast iron. An F1 car stops on carbon-carbon, which means carbon fibre held together by more carbon. The FIA does not order teams to use it. The technical regulations simply list carbon-carbon composites as a material allowed for friction materials, and everybody takes the offer, because nothing else survives the heat.

Brembo, who supplies the grid, stacks roughly 40 layers of carbon fibre into a disc shape. A machine called a needler punches thousands of needles through the stack as it spins, stitching the layers together so heat travels the way the engineers want it to. Then the stack goes into a furnace running up to about 1,482 degrees Celsius, where carbon-rich gas soaks into the weave and leaves solid carbon behind in every gap. Add the machining, the drilling, the coating and the inspection and one disc takes about four months. Brembo builds only around 3,000 of them a year.

The whole corner is one heat problem. The pads make the heat, the holes throw it out of the carbon, and the aluminium bell keeps it away from the wheel and the tyre.

Why There Are a Thousand Tiny Holes in It

Look closely at any F1 disc and the outer band is perforated like a speaker grille. Those are ventilation holes, and they are the single biggest reason a modern disc survives a race. Air gets pulled in at the inner edge, runs through the channels, and exits at the rim carrying heat with it.

The count has exploded. A Brembo disc in 2002 had a maximum of 72 holes. By 2016 it was 1,100, and in 2020 a high-cooling front disc ran up to 1,480. Then the FIA set a 3mm minimum hole diameter for 2022, which pushed the count back down to roughly 1,000 on the front and about 900 on the rear. None of it is guesswork. Brembo runs the airflow through simulation and reshapes the channels until the heat comes out evenly.

The Window Is 350 to 1,000 Degrees, and Both Ends Hurt

Carbon brakes have a working range, and Brembo puts it between 350 and 1,000 degrees Celsius. That is the strangest thing about them. A cold carbon disc is a bad brake.

Run them too cold and the friction surface glazes over, grip drops and the car will not stop the way the driver expects. That is why you see drivers weaving and stabbing the pedal on out-laps. Run them too hot and the friction material burns away, the brake fluid boils into vapour so the pedal goes long, and if wear eats into those ventilation holes the disc itself can come apart.

There is no easy fix. Article C11.5 of the regulations is one line long: liquid cooling of the brakes is forbidden. Every bit of temperature control comes from airflow, which is why the brake ducts inside the wheels are such fussy pieces of carbon, shaped to feed the disc and the calliper without wrecking the car's aerodynamics.

A road car brake works from cold. A carbon brake has to be warmed into its window and then held there for two hours, using nothing but air.

The calliper has its own heat limit, and it is far lower than the disc it is clamping. F1 technical writer Craig Scarborough put a number on it earlier this season while looking at a Williams front calliper.

A couple of blurry shots of the Williams front brake caliper. Brakes can be bigger and more complex this year. Notice the 'pins' (as @BremboBrakes call them) to help cool the caliper from its max 210°c #F1 #F1tech
- Craig Scarborough (@ScarbsTech) March 6, 2026

What Actually Changed for 2026

Here is the part most fans missed under all the noise about the new engines and the new wings. The FIA reopened the brake rules, and the numbers moved in every direction at once.

Every one of these numbers is pulled straight from the FIA technical regulations for each season. The front disc got bigger, the rear disc got permission to shrink, and the holes got permission to multiply again.

One change drives all of it. The MGU-K, the motor that harvests energy under braking, jumped from 120 kW to 350 kW for 2026. Slowing the car is now mostly the motor's job at the rear, so teams can fit much smaller rear discs and hand the work to regeneration. That is why the FIA wrote in a safety floor: whatever the hybrid system is doing, the rear friction brakes on their own must still produce 2,500 Nm at each rear wheel with no help from the power unit. If the electronics quit, the car still stops. We covered how the pedal talks to that system in our breakdown of F1 brake-by-wire.

The front went the other way. More energy going to the rear motor means the front axle picks up a bigger share of the actual stopping, so the maximum front disc grew by 15mm. The thicker 34mm limit and the smaller 2.5mm hole minimum exist for the same reason: more room to drill more cooling. Brembo's F1 customer manager Andrea Algeri has called this the biggest change on the calliper side in 20 years. One more rule backs that up quietly: discs, pads, callipers and master cylinders are now Open Source Components, so a team's design has to sit on an FIA server where every rival can use it.

The Rules Go Out of Their Way Not to Help the Driver

Read Article C11 and a theme jumps out. The brake system is allowed to be exotic, and it is not allowed to be clever. No anti-lock: no braking system may be designed to prevent wheels from locking when the driver hits the pedal. No power assistance, so nothing may raise calliper pressure above what the driver's own leg put in. Nothing may be pre-set, and asymmetric braking, where one side of an axle grabs harder than the other, is banned outright.

Lewis Hamilton locks the front left tyre under braking in his McLaren, smoke pouring off the flat-spotted tyre, showing why F1 cars are banned from running ABS — This is what no anti-lock looks like. Lewis Hamilton locks the front left into the hairpin at Suzuka, and that puff of smoke is a flat spot being ground into a tyre he has to live with. (Photo: Michael Elleray, CC BY 2.0, via Wikimedia Commons)

What You Will See On Track

Now the payoff. At a night race, watch the inside of the wheels into a heavy braking zone and you will see the discs glow orange through the duct openings. That is not a camera trick, that is carbon sitting in the upper half of its working range.

Watch for grey dust blowing off the wheels on a long run, which is disc and pad material leaving the car. Watch a driver miss the braking point, lock a front and trail smoke exactly like the photo above, because the rules will not save them. And watch how much the brakes shape a weekend. Brembo rates Baku four out of five for brake difficulty with 11 braking points a lap, while Monza and Bahrain are the only circuits it rates a full five. Suzuka and Silverstone sit at one, where the problem is the opposite one: keeping enough heat in the discs to make them bite.

The Bottom Line

An F1 brake disc is a four-month-old piece of baked carbon that has to be cooked to 350 degrees before it works at all, cooled by nothing but air, and stopped from doing anything smart by the rulebook. In 2026 the front one got bigger and the rear one got smaller, and the reason is a hybrid motor that now does most of the slowing down for free.

Fly the Flag on Race Day

If you are watching Baku this weekend with a new appreciation for what is happening inside those wheels, we keep a rack of real Formula 1 gear in the F1 collection. A few that are in stock right now:

And if you want to go deeper on the rest of the car, start with our breakdown of F1 tyre compounds and degradation. Brakes and tyres are the same argument from two directions.