How Much Should You Trail Brake? By Corner and By Class

Trailing the brakes feels more like an art than a science, because you cannot really coach or teach a driver the exact way to do it. It's a skill learned through practice, by repeatedly pushing yourself and pushing your braking points.

And when you do that, you end up trailing the brakes automatically, because it becomes the only option. If you don't want to miss the corner, or worse, end up in the wall, you have to keep holding them.

Why nobody can tell you exactly when to release

Trail braking is all about holding the brakes, but it really arrives as a necessity. You hold them because that's the only way to stop the kart. Then, naturally and without much thinking, you come progressively off them, and it happens in a fraction of a second. A tenth, two tenths, who knows.

The driver isn't conscious of it. If you asked me how I release the brakes going into a corner, I'd tell you honestly: I don't know. I'm just doing it.

If I told you to come off the brakes the moment you feel the inside rear wheel lifting, that would be nonsense. I'd just be trying to sound clever.

I'd rather not overcomplicate it, because to become a professional racing driver you need to feel. Robots do what they're told. They don't improvise, and they don't adapt to conditions.

And even a coach who gave you a precise instruction would effectively be lying to you. You cannot say "come off the gas at 637 meters" or "release four meters before the apex". How would you even measure four meters? You could talk about kart lengths, but at that speed you can't really tell. You can't say "wait 1.3 seconds after braking, then release". It doesn't make sense.

We can give you the direction. You go out there and find the route.

The rule of thumb, by corner type

That said, there is a rule of thumb, and it holds regardless of what class you drive. It's built on corner type, not on the badge on the bodywork.

• Slow corners: trail a lot. It should almost feel like you're holding the brakes until the apex. This is the case above all when you arrive at high speed and need to stop efficiently in a heavy braking zone.
• Medium corners: come off the brakes noticeably before the apex. You want to feel yourself getting on the throttle a bit before the apex, which means you must already be off the brakes.
• Fast corners: you don't trail at all. If you touch the brakes it's a tap, not a smash, and definitely not a trail. Often it's just a lift, or flat.

There's an exception inside the slow-corner rule too. If you arrive at a slow corner from another slow corner with no real straight in between, you won't need to trail much at all. You might just tap them. That's the real world, and it's exactly why "hold to the apex" is a rule of thumb rather than a rule.

Shifter karts trail the most

If you ask me which class needs the brakes most, and needs to trail them deepest into the corner, it's shifter karts. KZ.

They have front brakes as well as rears, and that changes the maths. You normally run a brake bias around 60/40 toward the front, or even 65/35, sometimes more. In cars you'd typically be around 58 or 59 percent. Karts run more front because rear locking gives you instability and stops you less efficiently, so you'd rather have the fronts do the work. And front lock-ups are rare unless grip is very low and your brakes are very good.

In a KZ hairpin you're making a V, in the line and in the speed. You brake very late and you stop more in the mid-corner than a single-speed kart would, so your minimum speed is lower than an X30 junior or senior. Their whole game is momentum, so their minimum speed will always beat yours. Yours is a different trade: you win it back on the entry with the brakes, and on the exit with the gears and the torque, which is also why the exit line goes tighter. The KZ braking piece goes through that in full.

In a KZ, hold the brakes pretty much to the apex. Not past it, that would be silly, because at the apex you also want to be on the throttle. It has to be a very fast transition off the brakes and onto the gas.

There's a second reason to hold them, beyond stopping. Because you're tightening the corner, you need the kart to rotate fast and aggressively so you can straighten up for the exit. And rotation comes from load.

When you brake, weight transfers forward and the front lowers. When you accelerate, it shifts back and the rear lowers. So trailing into the apex keeps the nose down, puts more weight on the front, and unloads the rear. More front, less rear, more rotation. Exactly what a KZ needs.

Where the time actually goes: a KZ against a senior kart

Put an OK senior kart and a KZ on the same track, say Lonato, and look at the data. The shifter brakes a lot later. The senior is quicker through the mid-corner, for certain, because it's far lighter and its lines are more open, so it carries much more speed at the apex.

Which means the KZ has to gain on the entry. If it doesn't, it ends up slower than the senior, despite being the faster kart on paper. The gap between an OK senior at world championship level and a KZ is roughly half a second, and it shouldn't be much more than that. Sometimes they're genuinely matched.

• Fast, flowing tracks: the KZ uses its gears and power.
• Twisty tracks: the senior is usually quicker.
• Lots of braking zones: the senior struggles, because that's where the KZ gains.

Single-speed karts: momentum changes the trade

Seniors, juniors and 60 Minis are a different animal. Their goal is mid-corner momentum, so the calculation flips.

If you gain one meter of entry braking but sacrifice too much minimum speed and exit, that's a bad trade for a 60 Mini. You have ten horsepower. Gain a tenth on the entry and lose two on the exit because your mid-corner is too low and your RPM is dead, and you're clearly worse off. So you trail a touch less, and come off the brakes just slightly earlier, than a shifter driver would.

But be careful how far you take that, because there's a trap waiting.

Don't slide into slow in, fast out. I hate that technique. Plenty of coaches preach it. The goal is fast in, fast out.

You still brake really late. You still stop enough to make the apex. And when I say "stop", I mean make the apex, not kill your speed. Those are different things, and confusing them is how overslowing starts.

This is also why single-speed drivers lose so much when they defend or overtake. A KZ defending a corner properly might lose a tenth. A junior, senior or Mini defending the same corner can lose three or four tenths, sometimes half a second, because forcing that tight V-shaped line kills the momentum they depend on and they have neither the gears nor the brakes to recover it. Which is precisely why they'd never drive that line on a qualifying lap.

Use the brakes as a balance tool

Here's the part most drivers never get to, and it's where trail braking becomes genuinely powerful. Your release point is a setup adjustment you can make mid-lap.

Ask yourself what you'd do with a lot of understeer. Come off earlier, or load the front more?

• Understeer: usually, trail deeper. Loading the front tire through weight transfer generates real rotation, and it lets you carry more entry speed at the same time. The exception is if you're already oversaturating the front tires, in which case releasing slightly earlier works better.
• Oversteer: trail a touch less. The front rises back up, the rear picks up load, and you get stability back.

You can reach the same lap time with two quite different setups and two quite different balances, as long as you adapt the braking to them.

In an ideal world the setup is identical every session, the chassis is identical, the track is identical, and you drive the same every time. That's a fairytale. What actually happens is the track changes, the kart's grip level changes, the tires wear. So you adapt, and your braking is one of the fastest levers you have. This is the same reasoning behind telling driver problems from setup problems, and it's worth knowing what understeer and oversteer actually look like in the data first.

Then go and look at it

Open PURPL and look at your brake traces, and at the trail braking channel specifically. It'll tell you plainly: did I trail a decent amount here, or did I barely trail at all and need to do more? For the mechanics of the technique itself, the trail braking guide covers how it works and how it shows up in data, and Senndit has a companion piece on the art of it.

Even comparing against yourself is enough to learn from. If you have a teammate to compare against, better still: you might see they hold the brakes a little longer than you into a corner, which tells you that you can brake later and stop more efficiently for the same exit. Or the opposite, that you're already braking too late and trailing too much to make the apex.

Sign up to PURPL free for your first 30 sessions, let me know how it goes, DM me on Instagram, and make sure to keep sending it. Ciao.