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TKART magazine How To | Set-up and driving tricks to reduce oversteer
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SET-UP AND DRIVING TRICKS TO REDUCE OVERSTEER

TKART Staff
26 January 2018
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1 INTRO
A previous article analysed understeer and examined the remedies available to reduce it. This article deals with the opposite problem, namely the phenomenon of oversteer.
Oversteer (which “experts” abbreviate to OS) occurs when the rear axle is weaker in terms of grip and has a tendency to lose grip first.
Unlike that which happens during understeer, in this case the driver is forced to reduce the steering angle or even steer towards the opposite side to prevent the kart from spinning.

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Oversteer involves the rear end losing grip and, in the more extreme cases, can cause the kart to spin.
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Oversteer involves the rear end losing grip and, in the more extreme cases, can cause the kart to spin.
2 SETUP
The two main, possible causes of oversteer are: incorrect set-up of the kart and tyre wear, especially the rear tyres. As in the case of understeer, it is always important to understand where the problem occurs: on entering the bend (where the kart tends to lose the rear end during braking); or when you begin to accelerate (causing the typical problem related to oversteer upon exiting the bend, often accompanied by a feeling of losing grip).
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Oversteer during the various sections of a bend
3 ENTERING THE BEND SET-UP
When the problem related to oversteer occurs at upon entering the bend, the rear end of the kart tends to become unstable under braking (i.e. you only need to turn the steering wheel slightly to spin the kart).
The phenomenon can be counteracted by increasing the rear track, closing the front convergence or reducing the rear track by a few millimetres.
As always, these modifications have an effect on the other sections of the bend, in particular: a narrower front track sacrifices front axle grip potential throughout the bend, therefore also in mid-bend and when exiting the bend where, perhaps, you were satisfied with how the kart responded.
Beyond the specific case, here is a general rule that those who are about to make modification to the set-up must always keep in mind: any modification can lead to an improvement during a certain section of a bend, but often have an effect on the other sections. The good mechanic knows how to strike the right balance; and a good driver knows how to provide the right information in order to do so.
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Reduce the front track
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Close the convergence
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Increase the rear track
4 MID/EXITING THE BEND SET-UP
Another case is when the kart enters the bend properly, but becomes too reactive or the rear end loses grip easily in the mid-/exiting the bend sections. To counteract excessive reactivity, it may be necessary to work on the front end, doing the opposite to what you would do to reduce understeer: therefore, reduce the front track or reduce the caster angle.
On the other hand, to make the rear end more stable, especially mid-bend and then during acceleration, you can try reducing (a few mm at a time) the rear track. Alternatively, you can try fitting a more rigid axle or longer wheel hubs.
Whereas in the first case the modification leads to greater rear end instability during braking, the second modification does not have any major effects on the first section of a bend, although it needs to be said that the latter modifications take longer to carry out.
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Reduce the front track
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Reduce the caster angle
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Fit a more rigid axle
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Fit longer wheel hubs
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