Useful Information for Farmers: Types of Agricultural Tyres and how to Choose them
There is such a wide variety of tyres for agricultural machinery the world of passenger car tyres wouldn’t dare to dream of. But how to choose tyres for tractors, combines, trailers and trailed machinery correctly?
Design of agricultural tyres is so complicated that for the first half century of their existence, tractors were equipped with metal wheels, without even a hint of a tyre and an inner tube. But over time, the advantages of pneumatic tyres became undeniable: high adhesion on different surfaces, low rolling resistance, strength and shock absorption from bumps. However, all these advantages will be seen only if the tyres for agricultural machinery are chosen properly.
Unlike tyres for passenger cars, agricultural tyres are divided by the type of load:
- Tyres for driving wheels. Their main task is to transmit high traction from the axis to the ground. Tread pattern is in this case also very important (mostly herringbone-shaped), as it should eliminate slipping on surfaces of various types. Since the basis mass of the vehicle is on the drive axle, high shock-absorbing properties of the tyre are a desirable characteristic, which is difficult to combine with a high load index.
- Tyres for steering wheels. As a rule, such wheels are smaller and less loaded. Their main feature is the tread pattern, which should provide low rolling resistance, but at the same time keep a given direction. This pattern has a pronounced longitudinal cut.
- Tyres for the carrier wheels. Their main purpose is to carry a trailer, a seeder, a harrow, etc., rolling with the least resistance. These models often have a small diameter, and in many cases a small load index, and the tread with a minimum area for grooves. Quite often agricultural tyres for the carrier wheels can be used as steering wheels on the tractor. But there are models suitable only for carrier wheels, for example, ВФ-242 4.50-10 66 or С-1 6.50/88-16 92 among Rosava-Agro.
Choosing Tyres for Combine Harvesters
Regarding the size and load index, the most important are recommendations of the manufacturer of agricultural machinery. The harvester is usually heavier than the tractor, and the traction of the wheels is lower. When choosing a tread, consider the type of soil on which you combine harvester usually operates: for example, sticky and moist soil will clog between the lugs, that’s why you’ll need a model with effective self-cleaning. The radial type tyre is always softer than the bias one, and the radial tyre allows operating with lower pressure. Due to this, it is possible to increase the shock absorption properties of the wheels, which has a positive influence on the operation life of some combine units.
Choosing Tyres for Tractors
The driving wheels of tractors are more important, their main task is to ensure the transmission of high tractive effort and this is the reason why the sidewall carcass and tread are made stiffer and stronger. Requirements to strength and durability in regions with stony soils and roads are higher.
Some tractors are considered not only a soil treatment machinery, but also a transport vehicle used on asphalted roads as well. Therefore, when purchasing wheels for a tractor for use in such conditions, it is recommended to choose products with a high speed index (at least 40 km/h) and increased tread wear resistance. An interesting fact is that tyres for tractors and combine harvesters are the most numerous in the Rosava-Agro model line. There are also tyres only for tractors, for example 15,5 R38 TR-07 and 13/6R38 TR-07.
Tyres for Compact Tractors and Equipment
Choosing tyres for a compact tractor is somewhat easier, dimensions and tread are the first characteristics to consider. Developed lugs are very important, their number and height affect the work on soils with different properties. The larger the distance between the lugs, the more confident the traction on wet ground will be, but the sooner the tyres will wear out, especially with frequent driving on the hard road surface.
Although it is possible, it is not recommended to use car tyres for compact tractors, cultivators and motor mowers, especially on the driving axles: even when the soil is a bit moist, such tread on the tractor will turn into a slick and skid. Deep and wide grooves, which car tyres do not have, are very important on wet ground for the steering wheels of trailers to two-wheel tractors.
Since the power of many models of compact agricultural equipment is limited, remember that large and heavy wheels reduce the traction characteristics of the machine.
Choosing Tyres for Trailers
Consider the type of road on which the trailer will be used most often. If it is mainly asphalt, choose options with a shallow tread, as they have a longer life and lower rolling resistance. For equipment (even trailed!) operating on fields and dirt roads, especially wet ones, tyres with large blocks and wide tread grooves are better. This also applies to trailed agricultural equipment – seeders, harrows, plougs, etc. Actually, efficient tyre ВФ-242 4.50-10 66 or unusual model С-1 6.50/88-16 92 are developed specifically for such technological farm equipment.
A Few Important Features
When choosing agricultural tyres, keep in mind some important features.
- The requirements to sizes for agricultural tyres are stricter compared to automobile tyres, the permissible deviations regarding the disk are usually specified by the manufacturer.
- Tubeless products are more convenient and cheaper to use, subject to good condition of the seating surfaces of the disks.
- Softer and wider agricultural tyres have lower specific pressure on the soil, that is, they compact the soil less, and sooner or later it will have its effect on the crop.
- Remember, that choosing agricultural tyres with a margin of bearing capacity provides an increased service life.
In conclusion, it must be said that only with correctly selected tyres all the characteristics of agricultural machinery intended by the designers could come to light.