Your combine-harvester only comes out a few weeks at a time, then is put aside for the rest of the year.
During this period, its agricultural tyres, which are often relatively new and in very good condition, are unused. Which brings up an interesting idea: why not fit these harvester tyres on your tractor which is used all year round? After all, it could prevent you from having to buy an extra set of tyres and therefore lead to immediate savings.
The logic seems quite compelling: making the most of equipment that has already been paid for, avoiding premature ageing of tyres which spend most of their life unused.
But behind this simple idea lies a substantial question: are harvester tyres and tractor tyres really interchangeable? Do they have the same technical characteristics, the same resistance, the same efficiency in the fields?
At first glance it seems feasible if the dimensions are similar. Yet each type of tyre is designed to meet specific requirements. And if certain configurations seem possible, others could endanger your performance, your soil… and the tyres themselves. So is it an easy way to save money or a false trail?
In this article, we analyse in detail the differences between harvester and tractor tyres, their potential compatibilities and the situations in which swapping them over could – or not- be envisaged.
Recuperating the front tyres of a harvester that is not in use to fit on a tractor is a legitimate temptation. However, this practice is not always appropriate for various reasons.
The main reason is the difference in design. A harvester tyre is effectively designed to carry extremely heavy loads, such as the weight of the harvester with its full hopper.
Its technology, in the case of IF or VF CFO (Cyclic Field Operations) tyres, allows it to carry up to 86% more load on a cyclic basis as the hopper fills up, without changing the inflation pressure.
Moreover, these tyres are not made to cope with the torque and continuous tractive force of a tractor. Engine torque, which is the force necessary to bring into motion an implement that is hindered by its attachment to the ground, puts the tyre sidewalls and casing under intense pressure.
A harvester tyre is not built to withstand this type of strain. This leads to premature wear, difficulties with motricity and, in the worst cases, to a breakdown (tear, burst tyre) which can cause considerable damage and immobilise your vehicle.
Inversely, the idea of equipping a harvester with tractor tyres could seem feasible, since both machines have similar sized tyres.
Here again, certain elements must be taken into account before opting for this solution.
Although tractor tyre dimensions can technically adapt to a harvester, the compatibility is limited.
And for good reason; the most load-resistant tractor tyres are often too bulky to adapt to combine-harvesters.
This can cause problems with the space required for the vehicle body or other machine parts. And this limitation considerably reduces the available options, making the choice of the right tyre size difficult and often approximate.
The main problem lies in the load capacity. Even the most high-tech tractor tyres, such as IF (Improved Flexion) or VF (Very High Flexion) tyres, are not designed to cope with the extreme cyclic loads of a harvester.
A harvester can reach a weight of more than 37 tonnes once the hopper is full, with this load fluctuating permanently during the harvest.
Smaller sized tractor tyres are therefore not sturdy enough to handle these weight variations, which leads to premature wear and a higher risk of breakdown.
The use of harvester tyres on your tractor can be envisaged, but many precautions must be taken (however this practice is not recommended).
The interchangeability of tyres between a harvester and a tractor is possible in very specific situations. This is the case in particular for work requiring very little torque. For example light soil preparation work, sowing or haymaking.
These activities with no torque are not intensely demanding in terms of engine power or the tractor’s transmission system, which reduces the risk of damaging the tyres.
However, you must bear in mind that this interchangeability is out of the question for heavy work such as:
This type of work places considerable strain on the tyre casing and sidewalls, and harvester tyres are not designed for this.
The design of the casing is very different for each model. The plies are not assembled the same way for tractor tyres, which have to deal with intense torque during the horizontal traction of implements while maintaining good stability, and harvester tyres which are designed to withstand a considerable vertical load linked to the weight carried.
Even in the limited cases where the tyre swap is possible, the technical limitations are multiple.
As such, swapping these tyres over should only be a one-off stopgap solution and never an option for regular, difficult or demanding work.
Choosing the right tyre is essential if you want to optimise the efficiency and profitability of your farm. Don’t forget that each type of tyre is designed for specific tasks and machines.
Investing in tyres that are adapted to each use is therefore the best way to optimise your equipment’s performance and useful life.
VF technology tractor tyres, such as Bridgestone’s VT-TRACTOR tyre, are working tools that are engineered to optimise traction and soil preservation.
They result in a very good work rate and offer many benefits:
Unlike tractor tyres, harvester tyres such as the VT-COMBINE tyre are optimised for their load capacity.
Their characteristics are designed to withstand the extreme and variable weight of a combine-harvester:
To answer the initial question simply and clearly: no, harvest tyres are not suitable for tractors or vice versa.
Even if some configurations seem compatible, the mechanical strain (load vs torque) and agronomic constraints (pressure to the ground, soil preservation) make it very unwise to swap your tyres over.
Each tyre has a precise role on the farm:
The Bridgestone-agriculture.eu blog is written and administered by tractor tyre experts who are available to provide you with the advice you need on the subject of your agricultural tyres. They allow you to maximise your productivity with information on all subjects linked to tyres: Technical data for agricultural tyres – Agricultural tyre performance – Air pressure advice, Solutions to avoid soil compaction – Sprayer tyre pressure – Why and how to ballast your tractor tyres – etc.
To take it one step further and increase the profitability of your farm, the blog Bridgestone-agriculture.eu provide a free, highly detailed eBook which explains the essential role of the agricultural tyre in your productivity.
Most people who read this article have also read some of the following articles which are listed by order of popularity: