How to choose the right tyres for a combine harvester?

First of all, take note of the possible dimensions for your machine. The manufacturers stipulate very specific dimensions that must be met when you decide to fit new agricultural tyres on your combine harvester.

And as your machine has to travel on the road before and after harvesting, it's also important to ensure that its total width remains within the limits authorised by the highway code.⁽¹⁾

First you need to choose the tyre diameter you would like: a larger diameter means a longer footprint so better soil conservation and mobility. And of course, the ratio between front and rear diameters needs to be considered when making your choice.

Below, we’ll show an example of soil stress map comparison from Terranimo® simulation:

• Left tyre : VF900/60R32 CEREXBIB2 (1.9m diameter), 15 000 kg and 2.6 bars
• Right tyre : VF900/60R42 CEREXBIB2 (2.12m diameter), 15 000 kg and 2.1 bars.

The pressures quoted above are for a load of 15,000kgs per tyre and 10 km/h cyclic speed. Smaller diameter tyre running at the higher pressure will create higher levels of compaction in the soil.

Soil compaction can become a problem when using heavy machinery, such as combine harvesters. In order to limit compaction, your machine needs to be able to run at low pressure... and not just at the front.

Like all farmers, you're probably looking to maximise productivity. And the bigger your tank, the less time you spend stopping to unload your grain tank at the edge of the field. But a bigger tank also means a heavier load, which is carried by your tyres. Their ability to carry a heavy load at the lowest possible pressure is therefore an essential criteria for choosing the right harvester tyres and maximising your yield.

Resistance is of course essential when you drive in places where your tyres can be damaged by stubble, metal parts or other elements. Furthermore, as combine harvesters are only used for harvesting, the tyres remain on the machine for a very long time, so this resistance must last over time. That's why we recommend choosing robust agricultural tyres that can withstand damage throughout their lifetime rather than interrupting your harvesting process.

Michelin has taken all the above points into account to develop efficient tyres that are adapted to your specific harvesting needs. And to meet them, we have designed two ranges of tyres: MICHELIN MEGAXBIB tyre and MICHELIN CEREXBIB tyre. What are the differences between these two ranges? That's what we'll explain below.

For enhanced benefits compared with MICHELIN MEGAXBIB tyre, we recommend you consider our premium offer: MICHELIN CEREXBIB 2 tyre. Here's why: