How Does Rear Track Width Affect Your Go-Kart's Handling?

Rear track width has a huge effect on the general handling of your kart. However, understanding rear track width can be extremely confusing, as there are a lot of contradictory articles and forum posts out there. So, it helps to learn how rear track width will affect your kart’s handling.

Rear track width can have a big effect on your go-kart’s handling. Widening your kart’s rear track width can add more grip to the rear, decreasing oversteer, and making it narrower can reduce understeer. However, there are other variables, so this might not be the first setup change you should make.

Below, we’ll go into more detail about the kinds of effects changing your kart’s rear track width can have, before listing solutions for some of the most common kart handling problems.

Table of Contents

What Is Rear Track Width On A Go-Kart?

Rear track width on a go-kart is the distance between the two rear wheels, measured from the outer edges of the tires. Track width measurements are very important to the setup and balance of a go-kart. It hugely affects the behavior of the kart while you’re driving it out on track.

Go-Kart Rear Track Width & Understeer/Oversteer

In simple terms, understeer is when you try to turn but the kart wants to go straight. The front tires lose grip and the kart struggles to turn in, drifting more towards the outside of the circuit. Oversteer is when the rear of the kart wants to pass the front end. The rear tires lose grip and you are essentially drifting.

Finding the right balance of oversteer and understeer is based on personal preference of the driver and on their driving style.

Smoother drivers, like Jenson Button, usually prefer understeer, whereas more aggressive drivers, like Max Verstappen, tend to prefer oversteer. There’s no right or wrong end of the spectrum, as it’s all about what makes you more comfortable in the kart and what allows you to go as fast as you can go.

How Track Width Affects This

So how does your rear track width affect oversteer and understeer? Well, there is a short and simple answer, and there is a longer, much more detailed answer. The short and simple answer is that widening your rear track width gives you more understeer (more rear grip), while narrowing your rear width gives you more oversteer (less rear grip).

Note: Altering your kart's rear track width shouldn't necessarily be the first thing you do to combat understeer and oversteer, as there are other variables at play.

At the end of the day, you need to fully understand the mechanics of the kart and the different variables to understand why your kart is understeering or oversteering. This is because some people find different results when making the same adjustments, due to the different variables involved.

Wheel Lift

In order to fully understand what you are doing when adjusting your rear track width, you need to understand how your inside rear tire is lifting off the track. This includes the rate at which that wheel lifts and how long the wheel spends off the ground.

I should add that having your inside rear tire lifting off the ground is a good thing. If you watch the top karting drivers, you can sometimes very clearly see that wheel lifting off the ground. This is how you get your kart rotated around a corner in the fastest way possible. But it’s not just about driver ability, as it’s also about having the right setup.

Understeer is when your inside rear wheel is not lifting enough, whereas having too much lift too quickly will cause oversteer and “snappy” turn-in behavior. Try to keep this in mind when adjusting your track width. Also keep in mind that it works in relation to your front track width, so only adjust one at a time otherwise you risk completely messing up your kart’s balance!

Making The Right Changes

If you have too much oversteer, you need to widen your rear track width. This means that your kart will have a lower center of gravity, and therefore it will be harder to lift that inside rear wheel.

On top of that, the wheel will also be lifting more slowly, causing more understeer throughout the corner. Widening the rear track width will expose more of the rear axle. This means it becomes softer and more flexible, which equals more grip at the rear.

Narrowing your rear track width will give your inside rear wheel more lift and cause oversteer. The higher center of gravity caused by a narrower rear track width will give the kart a quicker and more responsive cornering ability.

Going Too Narrow

When your track width becomes too narrow, it can cause an overload on the outside rear tire, which can cause a sudden loss of traction and you might find yourself either spinning or having to constantly catch the oversteer.

Karts with narrower rear track widths can feel a lot more unpredictable through corners and they become more difficult to control when driving on the limit. They will also become more prone to hopping through corners.

Hopping Or Bogging Down Through Corners

Getting Bogged Down

My kart had a problem of bogging down in tight hairpins for a long time, and I could never get a quick exit out of these corners. I tried different driving styles and looked up YouTube videos to try and figure out what was wrong with my driving technique, and I was adjusting a lot of different elements on the kart to try and solve this problem, but nothing seemed to work.

I could still see all of my competitors accelerating out of the hairpins at almost double the pace I was. It was incredibly frustrating to physically see myself losing three tenths of a second per lap just through one corner. The one variable I did not adjust is the rear track width, and this is a common solution to that exact problem.

Hopping Through Corners

Another issue that can be caused by running the wrong rear track width is the kart hopping through corners, this can also be caused by bumpier circuits. In both these cases, it is advised to increase the rear track width until the issue is solved. You will need to do this will small adjustments and frequent testing in between to ensure you don’t mess up other aspects of the kart’s handling.

As mentioned earlier, widening the track width makes the axle softer and more flexible in order to absorb the bumps and reduce the hopping effect through the corners. This is also useful advice when it comes to bumpier street circuits.

How The Weather Affects Go-Kart Track Width Setup

The weather can also play a role in determining which track width setting you should run on your kart. Different weather conditions mean that you need to adapt your driving style and kart setup accordingly. Some will need more oversteer and some will need more understeer.

Colder weather and slippery track conditions will require you to run a narrower track width because of the lack of grip caused by the colder track surface and cold tires. Running the narrower track will increase the rate of lift to the inside rear tire and allow the kart to rotate as quickly as possible.

When the weather is hotter and the track surface is stickier, increasing your rear track width will give you more grip. These are all dependent on weather and track surface conditions, so be sure to make small adjustments to your rear track until you are happy with your setup.

How To Adjust Your Kart’s Track Width

The specifics of adjusting your kart’s rear track width will vary depending on your chassis. However, it’s usually done by loosening the wheel hubs and sliding them either in (narrower) or out (wider) along the rear axle. If you do this, be sure to use a tape measure, from the outsides of one rear tire to the outside of the other rear tire.

Move both rear tires the exact same amount, unless you want to adjust for other imbalances in the kart. Using spacers on the inside of the wheel hubs can help you to accurately measure how much of an adjustment you are making.

When testing your different rear track width settings, always make your adjustments by 10 mm at a time (5 mm on each wheel). This is the general recommended amount of adjustment, and you should be able to feel the difference in the kart with each adjustment. Also keep in mind that the maximum rear track width as per karting regulations is 1400 mm.

Do not tamper with any other variables. Just change the rear track width little by little and see what it does for you. Write everything down, from the temperature to your setups and lap times, and how the kart felt to you, and keep this information for future reference.

KEY POINTS
• Adjusting your rear track width can affect how much oversteer and understeer your kart has

• It’s usually fairly easy to adjust your kart’s track width

• Always adjust it in small increments and test to see its effects before changing it further

Troubleshooting Go-Kart Handling Problems

Problem: Lack of traction when exiting corners (oversteer after the apex of the corner)

Solution: Decrease rear track width

Problem: Oversteer upon corner entry (the kart is loose and sliding before the apex of the corner)