Do Go-Karts Have Differentials? Why Don’t They?

Go-karts are incredibly simplistic vehicles that are designed for cheap and easy maintenance. Despite their tiny size and light weight, they can still corner at very high speeds, and they’re more nimble than a car. So, you might be wondering if go-karts have differentials.

Go-karts don’t have differentials as they use one fixed axle at the rear of the kart. Both rear wheels will spin at the same speed, so the inside rear wheel needs to lift off the ground for the kart to achieve maximum rotation. Karts also slide or drift through most corners because of the axle.

The axle plays an important role in a kart’s handling. While a car’s suspension is much more complex, a kart is much more basic, but it can still maneuver much more nimbly than a car even without a differential. We discuss exactly why this is the case in more detail below.

What Is A Differential?

Let’s first get into what a differential is before we look at why karts don’t have one. Differentials are used on cars to help them corner. Without a differential, it’s likely that your car wouldn’t be able to turn around corners safely and effectively because of physics that we’ll look into shortly.

A differential is a set of gears that transmits engine power to the wheels and allows them to turn at different speeds. The gears will transfer different amounts of power to each of the driven wheels (front wheel drive, rear wheel drive, or four wheel drive). The differential is kept in a housing alongside the transmission.

Why Is A Differential Necessary?

Differentials are important systems for cars because of the physics involved in how a car turns around a corner. When a car turns around a corner, the outside wheels need to travel further than the inside wheels. 

This means that the outside wheels need to rotate faster in order to keep up with the inside wheels and keep the car stable while it’s rotating and leads to tighter turns. The differential therefore delivers different amounts of power to the inside and the outside wheels, which allows the outside wheels to rotate faster than the inside wheels.

With a differential on the car, the car will rotate much tighter around corners. But without a differential on the car the outside wheel is likely to slide around corners as it loses traction while trying to keep up with the inside wheels.

Pushing A Trolley

One of the best ways to grasp why a differential is so important is to think about pushing a shopping trolley. When going around a corner, you need to push the outside of the trolley harder to get it to rotate faster and turn tighter.

For example, if you’re turning your trolley to the right, pushing harder on the left hand side of the handle compared to the right side of the handle (or even pulling the right side of the handle) will cause the trolley to turn much better. Cars work in much the same way, and this is essentially what a differential does for a car.

NOTE: Differentials are clearly quite complex components and they come in various shapes and sizes, but this simple explanation hopefully explains the key point that they’re important for helping the vehicle turn.

4 Reasons Why Go-Karts Don’t Have Differentials

1. Karts Use Direct Drive

Karts don’t use differentials because they use direct drive. There is just one single, solid axle at the back of the kart that is driven directly by the engine. This means that there is no way for the two rear wheels to be controlled independently of one another.

If a kart were to have a differential, it would need an entirely different axle system to be built and integrated into the rear of the kart. This would cause further problems for karts like more expenses and complexity that could take away from the purpose of karting, which is to be the purest form of motorsport.

2. Karts Are Easy To Maintain

Go-karts are meant to be easy to maintain. Due to their small frame and simplistic mechanics, karts are easy to take care of. Although they do require frequent maintenance, everything can be done within a decent space of time before heading out on track for a day of driving.

Karts might be sensitive machines, but the mechanical elements used on them are fairly basic. From the two-stroke engines to the carburetors and even the braking systems, there’s not much on a kart that’s too difficult for the average driver to work on. You don’t even need to be a mechanic to be able to maintain a kart and keep it in racing trim.

If karts were to have a differential, they would become much more complex to maintain and repair. Differentials create more complexity in vehicles due to the moving parts, and although it is possible to learn how to maintain them, it would still detract from the simplicity and ease of go-kart maintenance.

3. Karts Are Cheap To Maintain

Just as karts are easy to maintain, they’re also incredibly cheap to keep in working order. It might not seem cheap at first, but compared to cars and other forms of motorsport, karting is one of the most affordable when it comes to running and maintenance costs.

This affordability is directly related to the simplicity of the karts. There are far fewer moving components, and also less complicated systems on a kart. This means that less money is required to keep those systems and parts in tiptop shape. 

As long as the kart is maintained frequently enough, you likely won’t be spending too much money on general maintenance and keeping the kart running whenever you get to the track. All of the maintenance on the kart can also be done by the driver, which reduces costs even further. If karts had differentials, they would also become more expensive to maintain and repair.

4. Karts Are Small

Another obvious feature of karts is that they are small. Many karts weigh less than 100 kilograms (220 pounds) in total and have a single seat for the driver. There is simply not enough space for a differential to be placed on the frame of the kart.

The two stroke engine is placed to the side and slightly behind the driver, which is connected directly to the kart’s axle through a chain. There’s not enough space in this section of the kart for a differential to be placed, as this would create a bulky and awkward section at the back of the kart.

How Do Karts Turn Without A Differential?

You might be wondering how karts can turn around corners and why they are so agile if they don’t have differentials. It all comes down to how the axle and the chassis work together at high speeds, and this is only possible because of how light a kart is. It’s not possible with a car because they are far too heavy for this concept to work.

With a rigid axle at the rear, karts rely on a jacking effect for maximum rotation around corners. The jacking effect is when the inside rear tire lifts off the ground and allows the kart to rotate using only the outside rear wheel instead (since it’s impossible for them to move at different speeds).

The inside rear wheel is lifted off the ground because of forces generated by the tires causing the chassis to flex. This allows the kart to rotate much quicker, much like lifting the inside rear wheel of a shopping trolley if you need to pivot it around a much tighter corner.

Through faster corners, it’s often not possible for the chassis to flex enough for the inside rear wheel to lift off the ground. In this case, karts often just drift and slide through corners as the outside wheels lose grip but the inside wheels still bite. 

What Is A Live Axle On A Go-Kart?

Live axles are the type of axles that are found on go-karts. It’s one shaft that laterally connects the two rear wheels. This axle has a sprocket on the right hand side, which is connected to the engine through a chain and a clutch. When the gas pedal is pressed, the driveshaft turns the clutch, which in turn pulls the chain and turns the sprocket and axle, allowing the kart to drive forward.

On the left hand side of the axle is the brake disc. The brake disc is placed in between the brake pads which will clamp onto the brake disc when the brake pedal is pressed. This system works with basic hydraulic pressure using brake fluid.

Live axles are solid and have no differentials, which means they make vehicles more difficult to turn due to both the wheels turning at the same speed. In order to maximize rotation, the inside wheel needs to turn slower than the outside wheel, which can’t happen with a fixed live axle.

Final Thoughts

Go-karts do not have differentials because they are designed to be small, cheap, and easy to maintain, and a differential would add complexity. The solid axle at the rear of the kart works because the chassis flexes, allowing the inside rear wheel to lift off the ground when the kart is cornering.