Authored by: Tractor tyre expert | 02 March 2023
Tractor power is not the only decisive criterion for optimal productivity. Although it is perfectly logical to give priority to power (in accordance with the size and weight of the implements used), there is another key factor that must be taken into account in order to get the most power from your tractor. This factor is often underestimated: it concerns the dimensions of the tyres or whether they are suitable for the work to be done and the actual weight of the implements drawn.
It is the tyres that transmit engine power to the ground. If they are not suitable or they are undersized, the tractor’s power cannot be harnessed to the full. This is why it’s vital to get the tyre dimensions right when you replace your tyres, especially if you decide to work with bigger, heavier implements.
To maximise performance, it is important to make the right choice of tyres. The wrong choice may lead to loss of traction, accelerated tyre wear and an overall reduction of productivity.
Each agricultural tyre model is designed for a specific use. Working with tyres that are unsuitable or too small can lead to many inconveniences.
If your tyres are too small for your implements or their load, the risk of slippage will increase, especially in wet conditions or on loose soil.
Tyres that are not the right size will have a smaller contact patch with the ground. They won’t have a large enough bearing surface for the weight of your implements, obliging you to increase inflation pressure to compensate for load.
Rolling resistance will increase and the tyre will sink deeper into the ground, damaging the soil as well as causing slip.
In this case, you will not get the most from your tractor.
In short, you will not be able to increase its load capacity since you will have to respect the load index recommended by the manufacturer in order to avoid damaging your tyres prematurely.
Your machine’s traction capacity will be too weak. This will lead to extra fuel consumption and a considerable loss of time.
By choosing a wider tyre series, you obtain a greater volume of air in your tyres without changing the rolling circumference linked to the drive ratio.
You can increase your tractor’s load capacity, which will allow you to work with heavier, wider implements to boost your productivity.
Without changing the height of your tyres to have the same wheel passage, you can choose wider rims by reducing their diameter.
The volume of air will be much greater as well as the load capacity.
UA tyre and rim size that is better suited to your implements increases the load capacity and allows you to use your tractor’s power to the full.
Your traction improves because the soil footprint is much bigger and the tyres have a better grip on the ground.
Tyres are particularly important for the tractor’s braking system.
Tyres with the right dimensions maximise adherence and transmit braking power to the ground better.
The brake force depends on the coefficient of adherence of the tyre to the ground and the total mass of the agricultural combination vehicle.
Tyre dimensions can therefore have an impact on braking, especially if the tyres are undersized compared to your trailer’s load. For example a 150hp tractor with a total loaded weight of 40 tonnes with its trailer represents an unsuitable load/power/braking ratio.
As the size of the tyres is generally consistent with the tractor power, if your trailer is carrying too much load, your tyres are unlikely to be the right size for this load.
During emergency braking, the brake force will be felt directly at the level of the tyre. The distribution of forces on each wheel is not the same.
The front wheels bear most of the strain and the transfer of dynamic load to the front axle may destabilise the combination vehicle.
The risk increases if the global mass is too high, if your trailer has to brake while cornering or going round a roundabout.
When the contact patch with the ground is too small, the tyres are unsuited and the braking distance will be increased by several meters before coming to a complete stop.
Agricultural tyre manufacturers are aware of the problems linked to the different size constraints associated with tyres.
They are constantly developing innovative, high-tech tyres to adapt to the type of ground, weather conditions and above all load management.
At Firestone, the Maxi Traction range offers a wide selection of tyre dimensions to cover all load and power options.
Designed using ultra-resistance and lasting components, this radial tyre has a robust casing with a reinforced structure which allows it to carry up to 30% more load than a standard tyre.
It is perfectly balanced and provides optimal stability in the fields and on the road, even in extreme conditions.
Firestone’s Maxi Traction tyre range helps to improve your productivity and reduce your operating costs:
Thanks to its supple, resistant sidewalls, the Maxi Traction tyre allows you to work at an inflation pressure of between 0.8 and 1.6 bar.
Its Dual Angle lugs provide better traction.
The Maxi Traction tread is designed using anti-wear components to resist abrasion on the road. Its reinforced casing allows it to carry a heavier load than a classical tyre.
Slip is reduced in the fields, which results in significant fuel savings.
The width of the tread and its overlapping lugs offer a smoother driving experience with greater shock absorption and excellent road handling capacities, even when loaded.
It is crucial to understand the importance of having the agricultural tyre dimensions that are best suited to your use, your tractor’s power and the weight of your implements.
Undersized tyres can lead to:
By choosing tyres with a high volume of air and wider rims with an appropriate diameter, you can:
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