The term ‘live axle’ is often met when reading about go-karts. This article will explain to you what is a live axle, its ups and downs, and how it differs from a dead axle and differentials.
Live axle design
It is a rear axle that delivers equal power to both rear wheels, independent of the system of the front wheels. Its design is such as the one very sturdy long shaft with its ends having wheels attached. Axle gets its motion with the use of a sprocket attached to the chain of the engine’s crankshaft.
Types of live axles
Live axles can differ in dimensions and size, some suitable for specific sizes of the kart itself.
Usually, installing a live axle requires several specific parts, so they come together in a kit, completed and ready for set up.
When choosing the live axle fitting for your go-kart, please consider several conditions, such as axle width, length, material, and related parts.
Positives of the live axles
The very first advantage that go-karts equipped with live rear axle are their acceleration effect. The wheels on the live axle get equal motion spin and thus rotate evenly.
The resulting effect is higher acceleration, allowing you to reach the top speed on a straight line much faster.
The next advantage the live axle gives you is the weight. Its simple construction excludes many parts, thus giving the economy in mass.
The third advantage comes from the previous one – simpler construction of live axles has fewer details in need to maintain, thus keeping such kart in order is easier.
And the final advantage is its low profile. Compared to other construction elements, live axles need less ground clearance, this giving go-karts a much lower center of gravity.
Negatives of the live axles
Unfortunately, the highly efficient power transfer to the rear wheel assembly of a live axle can also bring its disadvantages, sometimes even overturning its main advantage.
The main feature that life axles have is the effective and equal power transmission to rear wheels. This works perfectly on straight parts of the go-kart racing track, but on turns, issues appear. Again, both wheels spinning at the same speed may cause your vehicle to skid.
During the corner, the distance that the inner wheel and the outer wheel are different, and this causes some trouble effectively handling the corners.
It could be wise to mention that the effect of a single axle will cause road bumps to spread evenly across the rear axle, but this minus is easily covered by the plus of the lower center of gravity.
Live axle and differential
When you look at a differential system, its method of work consists of the independent transmission of torque to each gear via a universal joint. In this complex, each gear can spin at different speeds. This helps to handle turns and improves grip, and thus is commonly installed on regular cars.
Many experienced engineers and designers say that the positives of live rear axle heavily outweigh their negatives, and thus karts are equipped with this design.
Live axle and dead axle
The main point that differs between constructions of a live axle and a dead axle, is the power distribution between rear mechanisms.
The construction with a dead axle is this: the dead axle does not transfer any torque to the wheels.
A ‘dead axle’ is an axle freely rotating, it is used to mount wheels and bearings.
The dead axle is only used to support the vehicle’s extra weight and is usually not met in go-kart construction.
Live axels’ length
Note that the length of your axle affects the handling: short axles make turning easier but can skid when braking.
Long ones are safer in that regard but provide less agility.
RWD and FWD cars
The position of live and dead axles defines the type of cars: in an RWD car, the front axle is dead and the front is live while in FWD cars it is reversed.
Tips for choosing the live axle
Harder and shorter axles perform better in corners when understeering.
On the opposite, when you need more drifting effect, take softer axles.
Choosing aluminum and carbon fiber will have a good effect on your hp/weight ratio because of their weight.
Now, after familiarizing yourself with this article, you know what is a live axle, how it works and compares to other rear systems of gears like dead axles and differential systems.
F.A.Q. about live axle
Live axle is presented by a mechanical complex where both rear wheels spin at the same speed thanks to being installed on a single axle.
As the key component in a go-kart racing vehicle, the live axle connects the rear wheels together and with the engine, also transmits power to both of them.
Compared to dead axles, go-kart live axle has several advantages, like higher acceleration, lighter mass, and lower center of gravity. When the system with a dead axle can spin each wheel independently and thus better handle corners, this is the only advantage of a dead axle over a live axle.
Go-kart live axle is a preferred design choice over a dead axle for several reasons, compared to dead axle design. Its only disadvantage is poor turn handling caused by the difference in distance between inner and outer wheels have to pass through, but in all other aspects live axle is the best choice for a go-kart.