Track Evolution In Karting (How To Read Grip All Weekend)

By Alessio Lorandi, 2013 CIK-FIA World Champion, KF-Junior. Updated on 22 October 2026.

Why is the track never the same twice, and how do you stay ahead of it?

The really cool thing about racing is that the conditions are never the same. When you go to a racetrack, the track and grip level will never be the same throughout the weekend, as you have probably noticed yourself.

That is a real challenge, and it exposes who the driver is that adapts the most in any condition, between grippy and slippery.

What is track evolution?

If we want to track a usual track evolution scenario, we will normally notice that on the first day, let’s say it’s a three day weekend, the grip will be quite low.

Especially if that track is not being visited a lot during the year, and if there was no pre-weekend testing.

For example, in the major CIK-FIA races and WSK races, you’re not allowed to drive during the race week except the actual moment the weekend starts. It starts on a Thursday for the Champions of the Future race, as well as the WSK race.

So you’re always going to find a little more green track on the first day, simply because nobody had been driving for a few days. Or maybe rental karts drove for a few days, and that’s even worse.

Why is the first day always green?

In some cases, as I said, you’re allowed to test the week before, and so you will lay down quite a lot of rubber.

But at the end of the day, after a few days of non-driving, the first day is always going to pick up a little bit of dirt, and so it will take a bit of time to clean it up properly.

Does a green track mean there is no rubber?

When we say the track is kind of green, we don’t really mean that there’s no rubber on the track. For sure the rubber is going to stay. You will never really find a track with absolute zero rubber.

Unless you go onto a street circuit like in Vegas, where you have a completely green track with absolutely no rubber. That is the extreme scenario. In fact the track evolution in that case is just huge.

Also in street circuits for formula cars, I mean, I raced in Macau, in the Pau Grand Prix, in the Norisring, and every time it used to take really a couple of sessions to even get any sort of grip on the track.

The track evolution there was just insane, and the driver really needs to adapt and show the best adaptability skills, because it’s really all about that.

Yes, the setups will also play a major part in making sure the kart is set up more towards when the track is going to be actually more grippy, because that’s what’s expected when it comes to quali and the race. But for the first test day it’s going to be very slippery, and that’s normal, and that has to be expected.

There have to be hundreds of drivers with new tires, ideally, that have to literally layer down the rubber in order to pick up any sort of grip.

Why does grip peak at qualifying?

Going into the second day, it starts to be more and more rubbered in. Of course the lap times come down significantly. But it really depends.

The day two gain comes from the surface, not from a change to the kart.

As I said, in a CIK-FIA race the track is already pretty good at the beginning of the weekend, because there had been plenty of pre-week testing. So the difference from the beginning of the week until quali is small. That’s easy for the drivers to adapt to, and it’s easy for the setups to be adapted to.

But pretty much 99 percent of the time, the grip level in quali is always going to be the highest, and the session before quali, because everybody’s putting new tires on that day.

Let’s say it’s day two, a hypothetical Saturday. Everybody’s going to go on new tires in the official practice before quali. Let’s say there are 300 drivers on the track, which is a normal number for WSK events. If 300 drivers each put on a set of new tires, that’s 300 sets of tires being layered down on the track, the best part of the tire.

What happens to the grip after qualifying?

As you’ve noticed, the track is not getting faster all the way through the week. In most tracks it’s not like that. In most tracks it gets faster and faster and faster all the way until quali, because everybody puts new tires until then.

And then after quali the times start to go up again. So they start to get worse and worse all the way until the heats and pre-final, where it starts to stabilise a bit.

And then when you go into the final, again everybody’s going on new tires in most series, and so the track again gets a bit quicker compared to the heats and pre-final.

So that’s normally track evolution. It’s a bit like an up and down. But after a while you start to anticipate what’s going to happen. You will never have 100 percent certainty on the track evolution, but based on experience you can get very close. If you want to make the most of that new-tire window, my qualifying tips go into it properly.

Do soft tires build grip faster than hard tires?

It also depends a lot on the different types of tires being used. If on the track there are a bunch of soft tires, from soft tire categories like Vega or LeCont, that’s always an instruction to expect times to really get faster and faster during the week.

If instead we are driving with very hard tires, and most categories during that weekend are driving really hard tires, then the times are not really going to improve that much. You will have to simply expect a lower grip level than categories with soft tires. And you can’t erase a slippery rubber layer by putting super soft tires on your own kart, I explain why soft tires are not always faster on track.

Why? Because soft tires can layer down way more rubber, because they get up to temperature way sooner than the hard ones.

They actually get up to temperature in a way that they pick up the grip level earlier, with lower temperature compared to harder tires, which require higher temperature.

And since it’s a bit of a vicious cycle, softer tires enjoy lower tire temperature ranges, so they actually start to switch on faster, and therefore they are going to pick up the grip earlier, they’re going to carry more speed into the corners, which automatically lays down even more grip.

You actually start to lay down grip when tires start to switch on. When the tire is just cold, you’re just sliding on the track, but you’re not really laying down rubber.

That’s something very important. You actually start to lay down rubber when the tire starts to get hot, very hot, when they get within the range. It is worth understanding the difference between grip-building slip and the good and bad of sliding, because they are not the same thing.

Why is the grip different from one patch of track to another?

So it’s really about learning the track DNA as well, and also trying to understand the track surface. Because not every track surface is the same as the other.

There are some track surfaces that are more abrasive, other track surfaces that are less abrasive. And there are surfaces that provide more grip overall than others that have just a lower grip overall. It really depends.

Then there are some tracks that even have different patches of grip, based on different patches of tarmac surfaces. So it’s also in that case kind of hard to predict the grip level in all the parts of the track.

So you have to again use your judgement, use your grip hunting skills and your experience, to tell where the grip is going to build up mostly and where it’s going to stay roughly the same.

How should you set up for a changing track?

You can always choose, as a driver or as a team, to set up the kart more for the qualifying, or you can set up the kart more for the heat races. It really comes down to the setup philosophy of the team.

But for sure, if you start playing too much with the setup when the track is super green, I believe that’s a mistake.

Because if you start to add so much grip, but then all of a sudden the track gets super fast and you start to have so much more grip, then you’re kind of screwed. You end up with way too much grip and the tire is not being utilised in the right way.

Why is the driver the grip hunter?

Never forget that the driver makes a difference. While you can rely on a strong team, a strong coach and a strong mechanic, the reality is that the driver is the one driving.

He’s the grip hunter, as I like to say. He needs to hunt for grip, and he needs to discover the grip immediately, as soon as he goes out on the outlap.

He needs to figure out where the grip has increased, or whether the grip has decreased in some corners. And you need to figure out where you can brake later and where you need to brake early.

So it’s all about adaptability and judging based on the conditions. But again, the drivers make the difference.

You can see that in Formula 1 as well. From the first practice on Friday until qualifying Q3, the grip evolution changes dramatically, especially in the street circuits, where the lap times come down massively.

How much time the track gives back from one session to the next is a question for your data, and that is what lap time analysis on PURPL is for. Here I care about what you feel in the seat.

And the drivers just have to adjust their driving styles by carrying way more speed, but in the right places. Because if you try to carry way too much speed in the entries of the corners, maybe that’s wrong. Because maybe the goal is to focus on the mid corner and the exit.

So you really have to judge it based on each track and each corner. It’s really important to always remember that the driver makes the difference.

What is grip hunting?

What I believe is the number one skill that a racing driver needs to possess is the grip hunting skill.

Yes, you heard me well. Racing drivers need to be grip hunters.

What do I mean by that? I mean that drivers need to really look for the areas on the track where there’s the most amount of grip.

They need to look for that racing line where there’s the highest amount of grip, which most of the time is not the geometrical, theoretical line.

Why is the theoretical line often wrong?

Most of the time we think, oh, we just have to do what’s right in theory and just apply that line everywhere, every corner, every track. And that would be easy, right?

But the reality is that many, many times the corners require a different kind of driving that is not the theory.

For example, in a corner where there’s a lot of positive banking, you will have to completely change your line. You may have to turn in earlier to catch the grip way earlier, even though that may look like an early apex in theory.

In that case what you care about most is the grip level, not the theory. So you have to look for the grip. You have to find the grip. You have to hunt the grip.

That’s what I really tell my drivers at Babyrace, that they are grip hunters. They really need to hunt for grip every time they go out on track. If you want to know why banking changes where the grip sits, I covered positive vs negative banking separately.

Why does the grip move from session to session?

Sometimes the grip level also moves within the same track, between different sessions. Why?

Because sometimes you have different categories on track that you may not have had before.

For example, you may drive all weekend behind a juniors class. So right after the juniors class you are, let’s say, a 60 Mini category. But then all of a sudden on a Sunday you drive right after the shifters.

And the shifters are going to drive in different parts of the track compared to the juniors. Because the shifters will drive mostly V-shaped lines, where they want to use all the brakes on the entry and use all the traction on the exit.

So again, in that case you have to be very strategic. You have to adapt really quickly to the changing conditions and hunt for grip. It’s not just from track to track, it may also be from session to session.

How do you adapt when everyone bolts on new tires?

And also when everybody goes onto new tires and the track gets really quick, you need to be very quick at adapting yourself and picking up the new grip level, and carrying the right amount of speed.

You can’t carry the same speed that you carried when the track was much slower. It just makes no sense.

And it’s not your data guy, your coach, your mechanic, your dad, your mum, nobody can tell you that.

Max Verstappen doesn’t have to be told by his race engineer that he needs to carry two kilometres an hour more in the mid corner when the new tires are on and it’s Q3. He just feels that. He has to hunt for grip.

Once you find the grip, you can carry more speed into the corner, so you can brake later, you can release the brakes and carry more speed through the corner, and you can get on the throttle earlier.

This is the driver side of why grip peaks at qualifying: the track changes, and you are the one who has to notice.

Does your body size change how you deal with low grip?

Sometimes the grip is not enough, and it may be easier for drivers that are taller, because they already load the kart so much and so they are better in lower grip conditions.

That was the case for me in my last year of junior. I was a bit tall compared to Lando Norris, who raced against me that year, and it was really hard to keep up with him in terms of speed, because he would be like 25 centimetres shorter than me.

So whenever it was grippy he would be a bit quicker than me. I would still be able to win lots of races despite that.

But then when it was winter time, and I was taller than him, I would have such an easy time compared to him, because I’d generate so much more grip and load on the tires, which he couldn’t.

So I was able to beat Lando Norris 18 times against seven in our 25 races, excluding the DNFs. Not to brag, just to prove that in some cases the grip level changes, and you have to do your best based on your body size as well as your setup.

If in the morning the grip level is low, somebody who is better in those conditions is going to excel more. And then if the grip level is really high at midday, you will struggle a little bit if you have too much grip on your kart.

Can a track walk tell you where the grip will be?

The whole point is that any time the track conditions change, any time the grip levels change, you have to adapt as soon as possible.

Track walks are really useful, because they can let you know in advance where the grip level is probably going to pick up, based on cues like elevation changes or banking areas.

I try all the time at Babyrace to tell my drivers that I want them to adapt really quickly to the conditions. Because there’s no point trying to brake as late as possible if you’re not on the grip, if you’re not on the right line.

And again, most of the time the right line is not the theoretical geometric line. Sometimes you may have to use a bit less track on the entry, which is counterintuitive, but it may be because there’s way more grip there, because there’s more banking, or because the categories before you drove tighter lines on entry since they have a gearbox.

Why is knowing a track too well a trap?

Remember that the track conditions are going to change a lot during the day and during the weekend. You may not have to drive in the exact same way as you used to drive at that specific track, even if it’s your local track.

It may actually be more difficult sometimes for locals, because they think: I’ve been driving this way the whole time, why should I change it now?

Well, because maybe there’s a completely different rubber compound this weekend. There’s way softer rubber, and maybe you have to carry way more speed in some areas because the track is a lot faster than normal. You have to find the exact places where the track has gotten grippier, so you know exactly where to find lap time. And every tire needs to be learned, the LeCont and the Vega are both very soft but the LeCont is impressively stable, I explain why every soft tire is different.

How do you score every corner out of ten?

You almost have to think about it in a gamified way.

Everywhere across the track, in that specific corner, you will have 10 out of 10 grip, or 9 out of 10, or 8 out of 10.

The goal is to optimise the time you spend on the 10 out of 10 grip. You don’t want to be on the 9 or the 8. You’ve got to be on the 10 out of 10, where there’s the highest amount of grip.

And the more you can spend time on the highest grip level on the track, in all the corners, the faster you’ll be, inevitably.

How do you start hunting for grip this weekend?

As a racing driver you need to always remind yourself that you are a grip hunter. You need to find the grip, and it’s going to change. The conditions are going to change. That’s what makes racing interesting.

The drivers that are the best are the ones who can adapt the fastest, and in the best way possible. So I think it’s not really about talent, it’s more about developing that skill.

Go out there and really feel the grip. Once you feel the grip, then you can carry the speed. It’s a connection between the grip hunting and the speed sensing skills. When you know where the grip is, you can carry more speed than the lap before.

If you want me to look at where you are leaving grip on the table, corner by corner, send me your onboard for an onboard review. And if you want to build this skill with me week after week, that is what I do in the 6 months transformation.

What do drivers ask most about grip?

What is track evolution in karting?

Track evolution is the way grip changes across a race weekend as rubber is laid down on the racing line. A track typically starts green and slippery on day one, gains grip continuously as more karts run, peaks at qualifying when everyone fits new tires, then loses grip through the heats before improving again for the final.

When is grip highest during a race weekend?

Almost always in qualifying and the session immediately before it. That is when every driver on the entry fits new tires at the same time, at a WSK event that can be 300 sets in a single session, and the soft outer layer of a new tire lays down the highest quality rubber.

Do soft tires build more grip than hard tires?

Yes, and considerably faster. Soft compounds reach their working temperature sooner, so they switch on earlier, carry more speed, and lay down more rubber, which builds more grip, which allows more speed again. On a hard tire weekend, expect the lap times to improve far less across the week.

Should you set up the kart for a green track?

No. Set up for the grip you expect in the next session. If you add a lot of grip to chase a green track, you will be badly overloaded once the rubber goes down and the tire stops working properly. Looking one session ahead is the whole skill.

What does grip hunting mean in karting?

Grip hunting is actively searching for the parts of the track that offer the most grip, rather than driving a fixed theoretical line. Grip is not spread evenly across a corner. Banking, elevation, rubber build-up and the class that ran before you all move it, so the fastest line is the one that spends the most time on the grippiest tarmac.

Why is the geometric racing line not always fastest?

Because the geometric line assumes even grip. In a positively banked corner you may need to turn in earlier to catch the grip sooner, and where a previous class has rubbered a different part of the corner you may need to use less track on entry. The theory describes the shortest path, not the grippiest one.

How does the class running before you change the grip?

Different categories lay rubber in different places. Shifters use V-shaped lines, heavy braking on entry and hard traction on exit, which leaves the rubber mostly in the mid corner. Juniors run a line much closer to a 60 Mini. Follow shifters and you can find the mid corner grippy while the entry and exit have gone away.

Are track walks worth doing in karting?

Yes. Walking the circuit lets you spot banking and elevation cues that predict where grip will build up once new tires go on, so you arrive with a plan instead of discovering it on the outlap.