Trail Braking

[ScoobyChris]

What is trail braking? In essence, it means continuing to brake after having turned in for a corner. The further you progress into the corner, the more you turn the steering wheel and the more pressure you release from the brake pedal. Typically, the procedure goes like this:

-You are hurtling in a straight line toward a corner;

-You apply the brakes - fully - while still traveling in a straight line;

-At some point, you release a little pressure from the brakes and start to turn in;

-As you bend into the corner and approach the throttle application point, you progressively release the rest of the pressure from the brake.

What's the point of it? Trail braking helps you rotate the car into a corner by controlling the transfer of weight onto the front tyres, giving them more stick, and thus compensating for any understeering tendency the car would otherwise have.

The alternative is: do all of your braking in a straight line, then release the brakes entirely, then turn in. The trouble with this technique is that when you release the brakes, weight - and therefore stick - will be removed from the front tires, just when you need them to be loaded enough to turn the car into the corner. So - unless the car is set up to be driven like this - it will understeer away from the corner. This is typical behavior for 'street' (aka massively understeering) cars that have been adapted for racing.

On the other hand, a 'proper' race car will probably oversteer if you don't trail brake. If you turn into a corner with your feet off both brake and throttle, the front tires will have all their traction budget available for turning while the back wheels will be doing some (engine) braking. Net result: oversteer. Application of the brakes settles down the oversteer by substituting a proportionately balanced loss of steering traction (because the brakes are biased towards the front). In fact, you use the brake pressure to control the rate at which the car rotates into the corner.

How much trail braking you do at a particular corner - i.e. what percentage of the corner is taken under braking - depends on the angle of the corner. For a 60

[m17rkj]

Good stuff that. my ibeefa responds well to trail braking, a little extra nudge on the steering as you turn in can get the rear a bit skippy, good fun!

[GTA_vRS]

I trailbrake (or sometimes just use a lift to help tuck the nose in) habitually on road and track. I find the weight balance of the car front to rear, affected by brakes and throttle, is more important to steering well than what you do with the steering wheel. On track, the benefits of trail braking are huge, unless you drive a really pointy car.

If you don't trailbrake, particularly on track, you can reach what I'd call a false limit where you understeer on corner entry, convinced you've reached the limit of the car, when in fact it's a technique problem.

I'm always very wary of journalists saying such and such a car understeers or oversteers, these are things the driver does to the car, not the other way around!

[Tom_vRS]

I have done this to great effect when pushing on really hard, and have done for a good year or so now. Its pretty easy to get right, and allows you to carry more speed into the corner, with less tyre squeal to boot!

[storm monkey]

I presume this forms part of the basis of left foot braking in rallying, as you "shift" the weight of the car from front to rear, and vice versa.

Phil

[sms]

does it say anything about it being for a rear wheel drive?

[faboka vrs]

Looks familar.

I always braked like this when briskly driving ever since I past my test.

[devonutopia]

Well, to put the other side, I was told I should not be braking to put weight on to the front wheels during the corner, as this is what unweights the back end and causes oversteer / skidding (essentially pushing all weight onto one front tyre) - I guess this is the case with full braking in the bend, but I was told to scrub speed off before the bend, and be just on the gas a bit through the corner. Also, I was told not to take the racing line but to position myself on the left (for a right hander) and by the centre line (for a left hander) to increase vision for myself and oncoming cars.

[KenONeill]

Works beautifully with Skodas, cos you get the weight transfer done before turning.

[faboka vrs]

Well, to put the other side, I was told I should not be braking to put weight on to the front wheels during the corner, as this is what unweights the back end and causes oversteer / skidding (essentially pushing all weight onto one front tyre) - I guess this is the case with full braking in the bend, but I was told to scrub speed off before the bend, and be just on the gas a bit through the corner. Also, I was told not to take the racing line but to position myself on the left (for a right hander) and by the centre line (for a left hander) to increase vision for myself and oncoming cars.

You got told the roadcraft way. Roadcraft isnt the fastest way but the safest way.

[ScoobyChris]

I agree with your approach, Jase and trail braking is not really a technique I've found a need for in road driving, although if you're comfortable LFB, it can be used to good effect in an auto where you can trail brake and feed power to keep the car perfectly balanced.

Should be applicable to all drives of car though as it's just a technique to shift weight over the front wheels, much like applying power is a way of shifting weight over the rear wheels.

Chris

[fab16v]

I've been trail-braking while pushing on or on track days for quite a while now. Was a technique I picked up back in my karting days and it's just stuck with the car too. Have always prefered driving with a light tail end when pushing on or racing. Is easier to carry on driving fast with a bit of oversteer than understeer. One of the people I've seen racing recently who uses it to good effect is Lewis Hamilton, especially at Monaco. Reminds me of my style when karting.

[sms]

he is an ex karter too.

[andypandypoos]

aren't they (almost) all ex-karters?

[ScoobyChris]

I'm pretty sure most of them start in karts before moving through the bigger and badder cars up to F1.... I was under the impression that Lewis was one of the few drivers who didn't use trail braking to unsettle the car and braked before the corner to drive round it on the throttle to maintain grip and minimise steering input....

Chris