Through the course of this article, I’ll be going over the most common reasons that a kart can start hopping through the corners of a race track and introduce ways to help prevent this event from occurring.
So, why might a go-kart hop in a corner? In hot temperatures, rubber is laid down on tracks more quickly, causing the inside rear wheel to lift as you corner. Next, the outside rear loses grip, before catching high grip quickly again. This creates a hopping, sliding action.
Everybody’s kart is different and because of that, there’s no one solution to the hopping kart conundrum! Below, I’m going to look at a host of other reasons why your kart might be making this strange movement around corners in hot weather.
Drop Tire Pressures
PSI is a pretty tricky subject to cover in the realm of go-karting, because tire pressures will vary widely between weather conditions and kart types. Typically, you can expect to see tires being inflated between 10 and 20 PSI under normal circumstances with the higher end being specifically used for wet races where grip is harder to achieve.
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On the opposite end of this scale, lessening tire pressure is a good way to deal with heightened grip; especially when you consider the fact that heat actually causes pressure to expand. If you fill your tires with 10 PSI, expect the pressure to have raised by at least 2 PSI by the end of the race.
It’s a common trick of the trade to underinflate tires in hot weather for that very reason. You want to give them some room to expand as the heat builds up, but you also want the tires to be firm enough to run without fear of damaging your wheels.
On the other side of the coin, over-inflation can lead to tire blow-outs which are disastrous for not only the kart wheels, but everything around that area if it’s a bad blow-out.
As with every recommendation that I’ll give, make sure to experiment with different tire pressures to find the best one for you. There’s no right or wrong answer because every tire brand and kart is different.
However, I usually ran something like 8 or 10 PSI max on hot days and upon making this adjustment with a few others I’ll mention, I don’t have any issues with my kart hopping around corners.
This might not even cross your mind, but have a good look at the seat position in your kart. It’s quite common for kart seats to be mounted high in the kart which works well for smaller drivers, but it becomes a huge detriment when racing in hot weather. It’s basically a component in the kart that’s higher up than the rest of the main parts and weight, which can result in tipping everything upwards.
If you’re at a loss as to why the kart keeps hopping, check out your seat height and try lowering it to different positions to practice with. Most drivers will find that they actually prefer a lower-set seat as it allows for better feeling in regards to turns, power and braking.
There’s a lot of debate in the karting community at large about what adjustments you need to make to your chassis if you’re hopping through corners. Until recently, everybody was in agreement that you needed to stiffen the whole chassis as the extra rigidity would help keep the kart planted, but as of late, the general opinion has shifted in the other direction!
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Although softening your chassis might seem pretty bizarre, this will actually allow the kart to stay planted on the outside rear even if you find your inside rear lifting through corners.
All things considered, this kind of tweaking is pretty low-maintenance and can be quickly achieved with a standard set of wrenches that you keep around for your kart. Grab a friend who’s handy with karts or refer to your kart handbook to find all of the necessary steps to adjust your chassis, and try softening it.
Don’t go overboard though! A chassis that’s too soft might run into havoc on the track and you might get splits or breaks. Keep it to small, subtle changes until you find the right setting for you.
If you haven’t had any luck with the above recommendations, it might be worth considering something a little more involved to help you out.
Go-karts are uniquely designed in the way that their rear is far wider than the front, and this is all due to down-force and how it keeps the rig at full speeds plus maximum grip. But when it’s almost too grippy on the track, this large difference in axle sizes can be more of a detriment than a benefit.
Typically, go-karts go by the ratio of 32mm front axle paired with a 50mm rear axle. If you’re still plagued by a hopping kart, you can invest in a 40mm rear axle instead and have that fitted, as this will actually reduce rear grip; not something you typically want unless you’re finding too much of it!
However, this change will be expensive and a huge hassle to get everything changed and fine-tuned all over again, because you’ll not only need a new axle but also rear hubs, sprockets, and disc carriers.
I’d say that this way of minimizing your kart hopping should be a real last resort, especially since it isn’t exactly fun or easy to switch out axles every time it switches between hot and regular weather.
Sure, there are loads of ways to minimize hopping through corners in terms of the mechanical changes that can be made to your kart, but I’d actually forego all of that and take a personal look at your driving first and foremost.
Similarly, when you’re in wet weather, you should be looking to take a different line around the track than when in hot weather. I always take a tighter line of entry into corners because this will avoid the most rubbered-in parts of the asphalt, greatly reducing my chances of the kart hopping due to over-gripping.
Another driver-based trick is to actually take a later entry overall which will allow you to throttle up earlier for a more straight-line exit; not normally recommended, but very helpful to avoid hopping.
And even if you feel the kart start to get away from you in the rear, it’s important to maintain equal, smooth throttle inputs. Jabbing at the throttle as you might feel inclined to do will be disastrous and actually cause more hopping. Don’t even get me started on brake usage through corners!!
The long and short of this is that a lot of the reasons why you’ll be hopping going into and around corners can actually be corrected with smooth, adaptive driving.
That isn’t to say that the adjustments to your kart aren’t viable, because they definitely help a lot! But rather than changing everything at once, try to make one change at a time and drive with the above skills in mind.
Kart hopping isn’t a simple fix nor an immediate one; it will all vary on your rig and driving style to find the right way to rectify it.
However, the extra time and effort spent identifying the exact cause of the hopping and being vigilant about adapting to that change is what’ll really set you apart as a great kart driver! No damages to your rig, no time lost during races… it’s a complete winning scenario!