Today’s go-karts are high-performance racing machines, capable of incredibly tight turns and staggering speeds. Despite their small frames and lightweight engines, they’re a hotbed of racing tech and talent. But how do go-carts stack up against traditional cars in terms of parts? Do go-karts have differentials?
Go-karts do not have differentials. Instead, when go-karts turn, the inner rear wheel lifts off of the pavement, allowing the outer rear wheel to spin faster. The front wheels are not connected by an axle, allowing them to spin independently.
Wondering about the physics behind this? Want to know more about differentials? Here’s everything you need to know about why go-karts can get away without a differential.
Why Don’t Go-Karts Have Differentials?
A differential is a complicated bit of engineering that sits in the middle of a car’s axle. When a car turns, the outer wheels take a longer path than the inside wheels. When the wheels are connected by a fixed axle, this can cause all sorts of problems. The wheel on the outside wants to spin faster than the wheel on the inside, so if the wheels are connected, one of them will have to slip and skid to allow the car to turn.
Differentials solve this problem by breaking up the axle with a set of gears. A differential allows two wheels connected to an axle to spin at different speeds while allowing the drivetrain of a car to power both wheels. When a car with a differential turns, the outer wheel is allowed to turn faster than the inside wheel, keeping traction on both wheels as the car corners.
Go-karts, unlike full-sized cars, are very light and made from flexible metal frames. As go-kart corners, g-forces make the go-kart tilt towards the outside of the turn. This has the effect of reducing the traction of the inner wheels and increasing the traction on the outer wheels. The sharper the turn, the more pronounced this effect is.
Because the inner wheel of the go-kart doesn’t have much traction, the go-kart’s outer wheel is allowed to spin as fast as it wants to. The inner rear wheel will still spin at the same rate, but it won’t have much traction on the ground. This allows it to slip gracefully while the kart completes the turn. With particularly sharp turns, the wheel will often become totally airborne and make no contact with the ground while the kart corners.
Go-karts don’t weigh a lot, allowing them to tilt like this as they turn. If a go-kart tilts too far, a rider can simply adjust their body weight to level out the kart. Crashes and tip-overs do happen, but it’s a lot less likely (and a lot less dangerous) than allowing one of your wheels to lift off in a full-sized car.
This process isn’t flawless, of course. On some turns and some karts, the inner rear wheel won’t lift up enough to slip against the concrete. When this happens, the turn tends to be a bit messy and drifty. Due to the lightweight nature of karts, however, this isn’t a big deal. Some drivers consider it part of the fun!
What is Jacking?
Go-kart experts use the phrase “jack” to refer to karts that are tilting over and are powered by one real wheel. Setting up a kart properly for a given course is a tough task. If the kart jacks too easily, it can be difficult to control, while if it doesn’t jack enough it can slide around corners instead. Serious kart enthusiasts will re-tune their carts for different courses, different riders, and even different weather conditions.
In addition to the low weight of karts, the flexibility of their metal frames plays a big role in their ability to jack. Flexible frames let the kart itself bend, facilitating the tilting process. This helps keep good traction on the two front wheels as the rear inner wheel lifts off.
Are All Go-Karts Rear Wheel Drive?
Go-karts are simple, light machines. In order to keep things simple, they’re steered from the front. This requires a steering mechanism, which is usually a rack and pinion system that separates both wheels.
The motor on a go-kart, therefore, is always connected to the back axle. As this is a solid axle, it’s able to power both wheels at once. Since there’s no need for a differential in a go-kart, this keeps everything nice and easy from a mechanical perspective.
While it’s theoretically possible to build a front-wheel-drive go-kart, you’d have to jump through a lot of hurdles to do so. The trickiest piece of the puzzle involves delivering power to both front wheels. This would require complex gearing and lots of additional parts, making it much more difficult and expensive to make than a traditional rear-wheel-drive go-kart. The extra complexity would also increase the weight, making the kart less fun to drive.
Can I Put A Differential In A Go-Kart?
Differentials are expensive, complicated, and heavy. While adding a differential to your go-kart might theoretically increase its ability to turn, it’s not free. Not only will the differential set you back a fair amount of money, but it’ll also increase the weight of your kart. Light karts are fast and fun to ride, while heavier ones start to feel like cars. Additionally, the differential adds an additional point of mechanical failure to your kart. Differentials don’t fail often, but they do fail, and this means you’ll have to spend more time and effort on kart maintenance.
The bigger point, however, is that the way go-karts work makes a differential somewhat useless. Installing a differential won’t stop the kart from jacking altogether. Instead, what’ll happen is the rear inner wheel will lift as the kart corners, just like normal, and the differential will allow it to spin at a different rate. Since the wheel is airborne, this won’t matter in the slightest.
There are definitely times when your rear inner wheel will make some contact with the pavement. During these times, you’d see some advantage from installing a differential. It’s a lot cheaper and simpler to adjust your kart’s jack, however, and the resulting kart is more fun to drive. This means that virtually all kart owners leave differentials off of their karts.