What Is Brake Bias In F1? (Fully Explained)

The braking system on a Formula 1 car is incredibly powerful and complex. Drivers can even change the way that the system operates on the fly by adjusting their brake bias. But you might be wondering what brake bias is and how F1 drivers are able to change it as they drive.

Brake bias in F1 refers to the balance of brake pressure between the front and rear wheels of the car. The system can be adjusted to use more braking pressure at the front of the car and less pressure in the rear brakes. A typical F1 brake bias setup might be 60% at the front and 40% at the rear.

The brakes on a Formula 1 car have a crucial job and they need to work perfectly all the time. Getting the brake bias set up correctly can mean the difference between pole position and qualifying outside of the top 10. We take a closer look at brake bias in F1 below.

Are Brake Bias & Brake Balance The Same Thing?

Brake bias is the same as brake balance. Both of these terms refer to the split between the braking force that is applied to the front and the rear brakes of the car. Brake bias is usually displayed in two different formats, but the values mean the same thing. It can either be presented as a percentage (60% front and 40% rear), or it can be presented as a ratio (60:40 or 60/40). 

The preferred setting is always to lean more on the front brakes as it makes the car more stable. Having more front brake bias means that the front brakes will work harder than the rear brakes because the braking pressure is geared more towards the front brake calipers. This also means that the front wheels tend to be the first ones to lock up.

Braking pressure is always set at 100% for all four brakes combined, but the amount of braking is then split between the front and rear wheels. That’s why brake bias is always measured as a percentage or a ratio that adds up to 100. This means you might see 50:50 or 55:45 for example.

How Brake Bias Is Displayed In F1

On a Formula 1 car’s steering wheel, you might see a driver adjust a knob mid-race and a big number come up on the screen on the middle of the wheel. This might display the number 56 for example. This would suggest they’ve shifted their brake bias to be 56% on the front, 44% on the rear. Alternatively, it might display as -1%, meaning they’ve moved it (likely backwards) by 1%. 

Drivers will likely be shifting it by about 1% at a time, as small changes can be all it takes to tweak the car’s balance to the driver’s liking for the next corner. Different drivers and teams will have different ways of displaying brake bias changes.

How Does Brake Bias Affect Handling?

Changing the brake bias will impact which set of brakes has the most braking pressure applied to them. The handling impact of changing the brake balance is so significant that drivers will always address this set up element during practice in order to get the balance of their car just right. 

Weight Of The Car

Brake balance is critical in Formula 1 because of the weight of the car. Because Formula 1 cars are relatively light, the direction that the car’s weight shifts makes a big difference in the handling of the car. The area that the weight of the car shifts into will generally have more grip because the weight forces the tires further into the tarmac.

When cars accelerate, the weight naturally moves backwards. When you brake, the weight will naturally move forwards. Think of being on a rollercoaster that’s accelerating down a steep slope, and you’re pushed back into your seat. Then, when the ride comes to a stop, you jolt forward as your body wants to keep moving forward due to its inertia.

Oversteer & Understeer

Moving the brake bias further forward will give the car more understeer. This is because there is more weight over the front end of the car and the front tires are already working hard to slow the car down. If you then try and turn the car, the tires will tend to break traction, leading to understeer.

The front wheels will also be putting the most work into slowing the car down, which means that they are the most likely to lock up first. Remember, a tire that is sliding produces far less grip than a tire that is rotating. That means locking the front brakes will instantly cause the car to understeer and run straight on.

Moving the brake bias further to the rear of the car will cause more oversteer. The rear tires will be doing more work, which frees up the front tires and allows them to work hard on turning the car, leading to a pointier front end.

However, locking the rear brakes can end in disaster. Instead of a lock up that leads to understeering and missing an apex or running wide, as would happen with a front lock up, locking the rear brakes can lead to oversteer that often in turn leads to a spin.

Generally, drivers tend to use more front brake bias because it makes the car much more stable than rear bias. Even though it leads to some understeer, a front lock up is easier to correct and the car can still remain fairly stable, but it’s very hard to correct a rear lock up.

NOTE: In an ideal world, the driver would never lock up, and if they did, all four tires would lock up at the same time. However, in practice, this rarely happens, so front brake bias is preferable.

What Locking Up Can Lead To

Changing the brake balance changes the way that the car locks the brakes. Formula 1 drivers are always on the limits of braking, so the slightest bit of additional pressure or the smallest mistake can lead to a lock up.

Lock ups can cause severe damage to the tires. Locking the brakes can lead to the tires flat-spotting, which is when the surface of the tire is worn down (and flattened) due to the friction of sliding across the tarmac. Flat-spotted tires may need to be changed as they cause massive vibrations that can slow the car down or damage it, or simply make it very unpleasant for the driver.

Wet Weather Conditions

In wet weather conditions, the handling of the car is severely impacted. Drivers need a car that is much more stable because the car produces less grip in wet conditions. In the rain, drivers usually battle with understeer because of the lack of grip due to the water on the track.

The front wheels are also much more likely to lock up in the wet because they are the first to hit the water on the track, displacing some of the water out of the way of the rear tires. When water gets underneath the tires their contact patch with the tarmac is removed, which causes them to instantly lose grip. When the tire loses contact with the tarmac it will lock up.

To get their cars to be more stable in the rain, drivers will tend to use closer to a balanced setup (50/50) or even more rear braking bias. This allows the front wheels to rotate more even under braking when racing in the rain. If the brake bias is moved too far forward, the front wheels will lock up too much when the driver hits the brakes, more so than in the dry.

KEY POINTS

• Brake bias essentially controls which tires lock up first

• It is an important element of the handling of an F1 car

• Drivers typically run more front brake bias, but different conditions require different setups

How Do F1 Drivers Change Brake Bias?

Formula 1 drivers can change the brake bias on their cars on the fly using their steering wheel. This concept was introduced in the 2000s when brake bias adjustment dials were added to the steering wheels of the cars. Drivers could now turn a knob on the steering wheel to adjust their brake bias while driving the car, rather than having to adjust the bias manually through the car’s setup.

Eventually the steering wheels on Formula 1 cars became so cluttered that some changes were required. Some teams put their brake bias adjustment instruments alongside the driver in the cockpit. 

But modern Formula 1 steering wheels have changed a lot, with a large chunk of the wheel now made up of the screen. The brake bias adjustment is still found on the steering wheel, and different teams will employ different buttons and dials for their adjustments. Brake bias adjustments tend to flash on the digital dashboard when the driver makes their changes, which you can sometimes see during onboards.

Why F1 Drivers Change Brake Bias During Laps

You may notice drivers constantly adjusting their brake bias during a qualifying lap, or sometimes during race laps too.. Drivers will sometimes change their brake bias 10+ times per lap depending on the number of corners on the circuit.

This is because they are trying to maximize every single corner on the track in qualifying in order to hook up the perfect lap. Each corner is unique, which means that the driver can benefit from different handling elements in each corner.

For example, a tight hairpin at the end of a long straight would require maximum braking performance to slow the car down from high speed to very low speed. In this case, the driver would move the braking balance further forward to make the front brakes work harder and get the car slowed down quicker. 

On the other hand, using front brake bias in a fast, flowing set of corners could cause the front tires to work too hard (as they’re on the limits of traction) and result in understeer. 

NOTE: Drivers will also change their brake bias depending on other factors, such as tire wear, tire compounds, and the weather

Final Thoughts

Brake bias is a powerful tool that Formula 1 drivers use every time they’re on the track. Changing the brake bias will affect the way that the car handles on track and the way that the car’s brakes behave. F1 drivers can adjust their brake bias on the fly, often many times during a lap!