When To Use Kerbs In Karting (And When To Avoid Them)

By Alessio Lorandi, 2013 CIK-FIA World Champion, KF-Junior. Updated on 17 October 2026.

Kerbs, kerbs, kerbs. Drivers believe that kerbs should be used at all times, especially the entry kerbs and the exit kerbs.

Most of the time, yes. But some of the time you should really stay away from them. And if you end up using the kerbs you’re not supposed to, and avoiding the ones you’re supposed to use, your lap times are going to suffer.

Should you always use the kerbs in karting?

Not always. But entry and exit kerbs, I’d say eight or nine times out of ten you should be using them.

So what’s the whole reason we use them in the first place? We want to open up the arc of the corner as much as possible.

We want to make the entry as wide open as possible and the exit as wide open as possible, so you can keep higher speed, have higher RPM all the way through, and therefore have a faster entry, faster mid speed and faster exit.

That’s the whole theory behind it. We open up the entry, we open up the exit, we make the arc wide open. And therefore we have an advantage over the drivers who have a tighter arc and stay narrower on entry and narrower on exit.

Because the whole goal of track usage is to keep up your RPMs. That is the whole goal. If you keep the RPMs up in the mid corner, you have more minimum speed and more exit speed. And ideally you can even drive with one sprocket less and have more top speed than everybody around you.

The best drivers are not genius. Many of them are just using the track more than you.

Where the kerbs fit in the full line, entry, apex, mid corner and exit, is in my article on the racing line in karting. This one is only about the kerbs.

Why can’t you use the apex kerbs in a kart?

Because a kart has no suspension. In formula cars you can use the apex kerbs, they’re very flat and the suspension makes it so much smoother to drive over them.

In a kart, most of the time the apex kerbs are unusable. If you try to use them you’ll probably bounce off and lose loads of time. I’d say 95% of the time you won’t be able to use them.

And it’s one of the most common unforced errors. A driver turns in too early, climbs the apex kerb, bounces off it, and loses like 3 tenths on the exit compared to the lap before.

At Lonato, if you try to go over the apex kerbs you lose so much time. But some tracks have flat ones. At La Conca and at Castelletto di Branduzzo there’s an apex kerb you can run. At Sarno there are a couple of corners where you can drive over them with no real side effect. Turn 5 there is banked, and it works well to kiss and clip the apex kerb a little bit.

Then the chicanes, where sometimes you drive over the kerb simply to make less distance.

And sometimes, if the kart has understeer, clipping the apex kerb gives you a bit more rotation. If it works without bouncing you off, try to reproduce it the next laps.

More on banked corners in positive vs negative banking.

When should you stay off a kerb?

If the theory says use the kerbs on entry and exit, then we would always have to use them, right? But the theory isn’t always the right solution on a real track.

Then a few more.

When it has just rained. A kerb that makes sense in the dry may be full of water, with a big puddle over it. So be open minded and change your decision quickly.

When the next corner is right there. In a sequence of corners close to each other, the exit kerb pushes you out and it’s too hard to bring the kart back for the next one. At Lonato you don’t use the exit kerb of the first and the second hairpin. At the third you do, because it launches you onto the straight.

On the out lap with low tyre pressures. I learned this at a Formula 3 test with Prema. They taught me not to use the kerbs on the out lap when we ran low pressures, because it increased the chance of a puncture and could damage the tyres. They were right. In a kart I’d do the same, especially in summer with very low pressures. More in why your out lap decides your race.

How do you know if a kerb is costing you time?

First, you feel it. When the kart is scratching on the surface, the seat is scratching, the tubes are scratching, that’s a kerb you want to stay away from. It’s going to slow you down.

Second, the exit. If every time you’re losing on the exit, even though you carry more minimum speed at the apex, and you feel the others pulling away from you big time, try the next lap staying away from that kerb.

Maybe there’s nothing wrong with the kerb and you’re losing the exit for other reasons. So it’s hard to tell. Record your onboard and check it after the session.

Did you leave 5 or 10 centimetres to the full kerb on the entry or on the exit, for no real reason, just because you throttled late and didn’t open up the steering enough?

And don’t trust one lap. Say you went on the grass on the exit once. The first thing your mechanic tells you is “stay tight on exit”. But watch every lap and you may see that on average you’re using too little track on the exit, with just a bit of kerb, while your teammates always get to the limit of dropping a wheel off it.

That is where somebody looking from outside helps. Send me your onboard and I go through your lines and your exits corner by corner in an onboard review.

Why is the theory kerb not always the fastest one?

Because of the grip. You don’t always have to drive the optimal geometric line. Sometimes you have to hunt the grip in different places.

Where there’s banking, where there’s elevation change, or where other categories are driving through, the shifter karts for example, because of where they lay the rubber on the track.

In a competitive field like WSK or a CIK-FIA European Championship, all the experienced drivers open up the track as much as they can, and they lay the rubber there. And believe me, just 10 or 20 centimetres of difference in line, on the entry, in the mid corner or on the exit, change the grip level massively.

So sometimes you change your line a little compared to the geometric one. And the same goes for the kerbs.

The rule of thumb is simple. You want to use all the track that makes you faster. Not the track the theory says you’ve got to use.

Can a kerb nobody uses be the fastest line?

Yes. And I learned it at Lonato, at the chicane before the last three hairpins, in KZ2.

On a testing day in January I found it by chance. I kept it almost flat and went super wide on the exit, with four wheels over the kerb, onto the extra red tarmac, bottoming pretty hard under the seat. It felt slower. Then I checked the time. Faster than the lap before.

“No way”, I thought. “Nobody else is doing it in KZ. If that was faster, they’d all be doing it.”

The 60 Minis, OKJ and OK were doing it. But in KZ everyone took for granted that you had to stay tighter and use the torque. And the exit kerb was pretty high. If you didn’t commit to all four wheels outside it, you’d bottom so hard and for so long that anyone could tell it was a time loss.

The data said it was faster than the tight line with two wheels over the kerb. Once I worked on it, about 1.5 tenths, counting the extra distance. The wide line made 4 or 5 metres more, but the mid exit speed paid for it, and some more. In karting, 1.5 tenths is massive.

I kept it in the pocket for qualifying at the Winter Cup. But my brother Leo, my teammate, found the same line.

In qualifying, 94 KZ2 drivers in three groups, I set my group pole with a 46.735, 1.5 tenths clear. Leo, in the last group, beat it by 0.042. Him P1, me P2.

So “nobody is doing it” doesn’t mean it’s wrong. Try it, then check the clock. Today, all four wheels outside that kerb is the only way to go fast there.

Does a kerb change during the day?

Big time. That’s why I keep what I call a “mental sticky note” while I drive. You notice something in the first laps and you use it on the next ones.

If the entry kerb feels slippery, maybe because of some humidity, and you lose the rear end, avoid it or use it a bit less on the next lap. Then towards the end of the session, when enough karts have gone over it, try it again. If it feels fine, use it again.

I see this very often at Lonato. The entry kerb of turn 3, the ex bar corner, and the entry of the chicane, turn 7, are always quite slippery on the first laps of the first session in the morning. Then better and better, and fine by the last lap of that same session.

When the track has just dried, the extra red tarmac beyond the exit kerb of the chicane, turn 8, stays slippery for a couple of hours before you can fully use it again.

And look at the kerbs while you drive. The mud on the exit kerbs. The marbles. Here are some of my notes from Franciacorta in KZ2:

• Turn 3, keep it flat and don’t clip the inside kerb.
• Turn 7, run full wide over the exit kerb and stay there.
• Turn 8, don’t turn in too late or the entry kerb will pull you out.
• Turn 11, let it run wide all the way through the exit kerb. If there’s too much marble, use less exit kerb.

How much kerb to use, if any, corner by corner, can make all the difference. How the grip moves through a weekend is in track evolution in karting.

Should you use the kerbs in the wet?

It depends on the class. There are two styles in the wet.

One is going over the kerbs at the apex. That’s more for juniors, seniors and the KZs. The other is taking wider lines to keep up the RPMs. That’s normally the Minis. But it can work for the bigger classes too. It really depends from track to track and from corner to corner.

Why go over the kerb? Because the equation of time is distance divided by speed. In single speed juniors and seniors, X30 or Rotax, you may lose a little minimum speed cutting tight over the kerb. But you make so much less distance that it pays the price.

Then you have to hook the kerb the right way. Hook it and the kart gets more rotation, and you make less distance too. Hook it too early and you get pushed out wide. Come off the brakes too early and you overshoot the kerb that’s supposed to hook you, go onto the rubber, and miss a ton of time. So hold the brakes until that kerb.

And watch for the puddles on the entry and exit kerbs I talked about above.

I remember watching Max Verstappen in karting in the wet. He was using the kerbs extremely well. He was like the only one who would hook them properly.

The full wet technique is in my wet karting tips.

Do you use the kerbs differently in a KZ?

Yes, often. In a KZ you brake more in a V shape to use the front brakes, and you V the exit too, trying to be as straight as possible, especially after the hairpins.

So if you drive a KZ with the single speed line, super open on the exit, the power pushes you out wide onto the kerb, or you have to release the throttle. It’s just a mess.

But don’t make it a rule. The chicane story above was in KZ2, and the fast line was the one the single speed classes used.

And watch out for the excuse I hear a lot: “I don’t need to use the full exit kerb because I don’t have enough bottom from the engine.” Check it in the data before you believe it. If you want that data read for you, upload the MyChron file from the session you just drove to PURPL, the app I built, and it hands back the three things to change next time out.

More on driving a shifter in my KZ driving tips.

Why does more kerb mean even more kerb?

Because think about it. You carry more speed on the entry by using more kerb, unless it’s super dirty or super steep. You open up the corner and make the arc wider. Then in the mid corner you have a lot more speed, and because of that you end up using even more track on the exit.

It’s kind of like a vicious cycle. The more kerbs you use, the more kerbs you need to use. The more entry kerb you use, the more speed you carry at the apex, and the more exit kerb you have to use.

And remember, in a sequence of corners you prioritise the one that leads onto the straight. More on that in how to prioritise exits.

Can kerbs hurt your ribs and your kart?

Yes, both.

The thing that hurts the ribs most is not the steady g-force. It’s the kerbs. Every hit smashes your ribs against the rib protector, and the protector against the seat. So you can still crack a rib even with a protector.

It happened to me. I was training a lot without resting much, smashing the kerbs in the wet at Franciacorta to go faster, and my seat was a bit too tight. I got some rib pain, I neglected it, it became a big one, and I had to stay away from driving for about two months. My ribs had small cracks.

At La Conca we used to fly with four wheels over the kerb at the chicane. They changed it in the last couple of years, it’s not as sharp now.

So use the kerbs wisely, and only where they find you extra lap time. If you smash kerbs flat out, first make sure the seat is not too tight. The full story is in rib protectors in karting.

And the kart. When you use a lot of kerbs you stress the frame so much. A tired frame can crack the day you hit a kerb. Keep that in mind when you buy a used kart.

How do you work out which kerbs to use on a new track?

Track walks. Not only the first time you go to a track, but again and again. You always have to relearn the circuit. You can always find hidden secrets about it.

On a walk you see whether a kerb is flat enough to use or too steep, whether it’s clean or dirty, and the grip, the elevation changes and the banking around it.

The goal is to use all the kerbs that are going to make you faster, and avoid all the kerbs that are going to make you slower. It’s as simple as that.

Double check with your coach too. And at the end of the day the lap time and the drivers around you tell you if it’s fast or not.

How to learn a whole new track is in the racing line article, and the circuits themselves are in the best karting tracks in Italy.

If you want to work on your technique with me over a season, that’s my six month training program.

Frequently asked questions

Should you always use the kerbs in karting?

Most of the time, yes. Entry and exit kerbs open up the arc of the corner, so you keep the RPMs up and carry more speed on the entry, in the mid corner and on the exit. Stay off the ones that are too dirty, too steep, under water, or that push you out before the next corner.

Why can’t karts use apex kerbs?

A kart has no suspension, so a raised apex kerb bounces you off and you lose more time than the shorter line gains. About 95% of the time you can’t use them. A few flat ones exist, for example at La Conca, Castelletto di Branduzzo and Sarno, and in chicanes you sometimes drive over the kerb to make less distance.

How do you know if a kerb is costing you time?

You feel the kart bottoming, the seat and the tubes scratching over the kerb. Or you carry good speed at the apex but the others pull away on the exit and down the straight. Try the next lap off the kerb, and check your onboard after the session.

Should you use the kerbs in the wet?

Juniors, seniors and KZs often go over the apex kerbs in the wet to make less distance and get more rotation, while Minis usually take wider lines to keep the RPMs up. Hook the kerb at the right moment and hold the brakes until it. Avoid kerbs with a puddle on them.

If you want me to look at your onboard and tell you which kerbs are making you faster and which are slowing you down, send it for an onboard review.