With go-karts being pretty stripped-back pieces of equipment in the motorsport sector, it’s difficult to know exactly what is included on them. Through the course of this article, I’ll be outlining how suspension works on a go-kart and look at how you can adjust this using different means.
So, does a go-kart have suspension? Karts are defined as ‘small, purpose-built racing vehicles with rigid frames and no suspension’. The chassis has enough flexibility to provide suspension, but must also be rigid enough to withstand cornering. Chassis stiffness can be adjusted with torsion bars.
Not having suspension on a motorized vehicle might seem strange, but it’s all part of how go-karting has stayed so popular over many years. Suspension is a tricky component to manage and this is made easier by the unique chassis design of race karts. Keep reading to understand more.
How to Adjust Suspension on a Kart
Just because go-karts are streamlined bits of tech when it comes to motorsports (especially when compared to race cars), it doesn’t mean they’re simplistic by any means! Originally, suspension wasn’t deemed necessary because it would add too much weight to the frame of what was supposed to be a lightweight vehicle.
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As karts have evolved over the years, the chassis itself plus a few other key components have become the key to unlocking how its suspension ‘system’ functions.
If you’re familiar with karts, you’ll notice that the base of it is made up of tubing. This material will come in different sizes depending on the size of the kart overall, but most adult karts will be made of 30mm or 32mm tubing.
The lesser size of tubing is considered better for a more flexible kart, essentially meaning that its suspension and ability to go over curbs is better than a stiffer variety, plus, it’s more lightweight. The larger size of tubing will make the whole rig stiffer without as much ‘give’, and this offers the driver better handling and better grip on the track.
Both sizes of tubing I mentioned are perfectly acceptable for go-karts, and it’s all down to driver preference as to what they want their kart to feel like. No one tubing size is better than the other; it’s just a different style of racing.
Axles And Spindles
Another way to alter your kart’s overall stiffness or flexibility comes in the shape of axles and spindles.
The axle is, purely and simply, a rod that connects the rear wheels together. As of late there have been a lot of regulations put in place by kart authorities that dictate a standardized axle rigidity in order to account for driver safety. Nevertheless, an axle will be more flexible dependent on the material and chemical composition it is made of.
A stiff axle will provide more rear grip through corners because it forces wheels to stay in contact with the track as opposed to allowing them to lift. A soft axle, therefore, will reduce grip and give the kart more overall flex.
Every kart chassis will be different, however, and newer designs are getting progressively more flexible as standard, so it’s always worth talking to a kart dealership or the manufacturer to discuss how to achieve various effects.
Spindles, which pair with wheel hubs, don’t offer such a wide variety of effects but you can switch out for different sizes to achieve slightly differing effects. The longer a spindle in its wheel hub, the more front grip you tend to get. And by the same token, a shorter spindle in a wheel hub will lessen front grip.
Another way to manipulate your suspension in a number of ways is how you position your seat in the kart. A driver’s body is oftentimes their greatest weapon; both in feeling how the kart handles, and actually handling the kart in different ways.
Central seat positioning is standard in go-karts, but some drivers opt to mount it askew to different sides depending on how the corners unfold at a specific track. A higher seat position will give the kart more flex, and a lower seat position will stiffen the chassis.
The Importance of the Driver!
Even if your seat is mounted at its highest, you as the driver will still be very close to the ground. This design is intentional as well as a means to make the most of a kart’s basic composition! It allows the driver to use their own weight to make shifts in the kart, and this is why you’ll see a lot of kart drivers actually leaning into corners and even tucking their head down on straights.
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The bottom line is that we’re the heaviest part of that kart! It’s important to use your body wisely while racing, no matter how many different ways you’ve implemented suspension-altering tactics such as axle stiffness, spindle size or seat position.
Can Tires Make a Difference in Suspension?
Absolutely! If you think about it, the tires on a go-kart are what is keeping the frame suspended from the ground, and they have to be inflated to a certain pressure in order to keep the tubing underneath intact.
There isn’t a concrete tire pressure you should be using, however; simply a range dependent on track conditions. I typically inflated my tires between 15psi and 30psi for my varied kart races over the years and never had any issues.
At times, if I felt that the kart was bouncing too much to the point of reducing my handling, a quick top-up of air pressure would stop the issue and essentially act as stiffened suspension.
As ever, when making changes to your kart, always make sure to make gradual adjustments. If you change everything all at once, you’ll probably find that the end result is too far past what you were wanting to achieve.
Say for example that your kart is too stiff and you’re getting too much grip, to the point of hopping through corners. To combat the issue, you switch out your rear axle for something softer and shorter with smaller spindles, you raise the seat and also release some tire pressure.
I can guarantee that you’ll now have a go-kart that is far too flexible and you’ll be missing out on grip where you need it!
Choose one component to tweak, give it a test, and if it isn’t resolved, try something else. Applying all of the ways to adjust your suspension all at once isn’t going to end well!
What About Torsion Bars?
Depending on the kart you buy, you might find that a torsion bar comes as standard on the rig overall. Mostly, however, a torsion bar is designed to add extra rigidity to your go-kart and therefore provide more grip, specifically to the front due to how torsion bars are installed.
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There is a collection of different materials used in the creating of torsion bars, and each material will have a different effectiveness in increasing rigidity. For example, a nylon bar isn’t as stiff as an aluminum one, so the latter will add more rigidity to the kart frame than the former.
Although this change is primarily felt in the front of the kart, the rear will also feel the same effects. It’s important, therefore, to only add torsion bars of lower rigidity and work your way up if you’re really struggling with front-end grip and too much flex. Running with a stiffened steel compound torsion bar might throw out your whole kart’s alignment!
A kart’s suspension, while not visible as it is in big buggies or on road cars, is a very real and tricky thing to work with. Because go-karts are pretty pared-down pieces of equipment, everything on the chassis and overall rig is designed to produce the best suspension possible without shock absorbers attached.
I often get asked why you wouldn’t simply put shock absorbers on a race kart, and I have seen some people experiment with them over the years. But, between race series not allowing shock absorbers as a standard rule of thumb, and the absorbers largely being obsolete compared to all the ways you can generate suspension differences I’ve already talked about, it simply isn’t worth it.
I hope that the information I’ve covered in this article about go-kart suspension has been helpful for you motorsport lovers out there! Never underestimate the power of a kart chassis in doing all the jobs it needs to, that’s for sure.