Understeer can best be described when the front of the kart doesn’t have the same grip as the rear of the kart.

A driver will begin to turn the steering wheel, but the initial response will have a slight delay before cornering. This is the ‘understeer’ sensation.

It can be also described as ‘push’, due to an imbalance in grip between the front and rear of the kart.

Understeer will most be felt in the wet weather conditions where the front tyres slide across the track surface and you are limited with front grip.

What does it feel like?

A driver is approaching a corner and begins to apply some steering input. But the front tyres haven’t gripped enough and the kart is tracking in a straighter trajectory than first thought. The driver will want to increase the steering input for the kart to turn, as they are feeling the kart ‘push’ and not steer to it’s intended location. However, the tyres are already beyond their grip threshold and cannot steer anymore, so applying additional steering doesn’t achieve the desired result. The problem with increasing the steering input, is that when the tyres actually grip, this can cause the kart to break into oversteer as it’s too much steering angle at the point of the tyres gripping.

What are the causes of understeer?

- Entering the corner with too much speed.
- Accelerating too early.
- Poor Kart Setup.
- Turning into the corner too early.
- Entering the corner with too much speed.

It’s possible to experience understeer by entering a corner with too much speed. There is only a certain amount of speed a kart can physically travel through a corner before it breaks traction. If you enter with too much speed, you will lose grip in either the front or the rear depending on your technique or kart setup.

Accelerating too early.

When a driver gets back onto the throttle too early this can induce understeer. The reason being is that if a driver still has some steering input in place, and hits the throttle, the karts wants to drive in a straight line rather than cornering. So a driver will then increase his steering input to defy science. If you are experiencing this, the ideal way to get around it is to be more patient before accelerating and allow the steering wheel to be much straighter (further around the corner) before applying.

Poor Kart Setup

Setting up a kart is all about gaining a good balance between front and rear grip. Generally if a driver is experiencing understeer it is likely they have too much rear grip which is causing an imbalance between front and rear that is not allowing the front to steer at its intended rate.

Turning in too early

When a driver turns into a corner too early, the radius of the corner is diminishing. So it requires more steering input to complete the corner. When they take a wider radius, the driver is able to make a smaller steering input, for longer, which will minimise the chance of understeer.

The three phases where a kart can understeer

-Entry
- Apex
- Exit

Entry – Generally if a driver experiences understeer in this section of the track it is due to the amount of speed they are entering the corner with. Too much speed, and a sudden turn of the steering wheel can lose front grip and initiate ‘understeer’. Another reason could be due to too much rear grip ‘pushing’ the front into understeer, so a mechanic would need to look at reducing the rear grip to give the kart a more equal balance.

Apex – Will be a mixture of speed too fast, the kart having too much rear grip, or if you choose to accelerate too early. As we mentioned above, if a driver is trying to accelerate before the apex, while still having too much steering lock applied, this will cause the kart to understeer.

Exit – accelerating too early will cause the kart to understeer from the apex through to the exit. A driver needs to apply the throttle slightly later with minimal input.

What Is Understeer?