TECHNICAL NOTES

Tyre Marking

Technical Data Symbols

Tyre size corrispondence

Load and speed tables

Conversion factors

Concept of the low pressure

 

The concept of the low pressure in TWIN and Extra Large tyres

The wide low-pressure TWIN and Extra Large tyres have special design that will improve your yield, simplify work, protect your soil and crops.

 

Solid construction

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 TWIN is a bias-belted tyre, a combination of the cross-ply and radial-ply tyre design. Basically the carcass is like the diagonal design, giving a strong and durable tyre. The sidewalls are thicker than with a radial tyre, and therefore more resistant to cuts and damage. Also, more lateral stability is provided from this design, giving increased safety on slopes.

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Extra Large tyres have a radial-ply tyre design. Soft and flexible sidewall, in combination with the belts, gives maximum performance in the field, excellent handling and comfort on the road.

Both tyre concepts can be used with low inflation pressure, which means low soil compaction, and minimum rut formation.

The TWIN tyre carcass is built up of several plies of crossed fabric. The tread surface is reinforced with extra underlying belts.
The Radial tyre carcass is built up of several plies where the layers go radially (straight over), from bead to bead. The tread is then strengthened with underlying belts. 

Large contact area

A belt beneath the tread gives a flat profile to the tyre tread and increases the contact area, spreading the load over a large area and increasing traction. TWIN e Extra Large might, in many cases, replace dual mounted standard
tyres. If, however, they are dual mounted, the vehicle flotation and terrain mobility improves even more.

High pull force

When the horsepower is used fully, a need for good and reliable traction is essential. That makes the construction and the tread pattern of the TWIN e Extra Large tyres advantageous.
With sturdy sidewalls and excellent tread pattern, a high degree of traction will be transferred to the ground with less slippage or ground damage.

Less soil compaction and damage

With the development of larger, heavier, and more efficient machines, soil compaction and damage follows almost inevitably. To prevent such damage however, the vehicles have to be equipped with low inflation tyres that manage to carry the heavy
loads and give the vehicle high flotation. The low ground pressure keeps the tyre on top of the soil, reducing rolling resistance. A wide tyre with a large contact area and a large air volume spreads the load over a bigger area.
The TWIN e Extra Large tyres have these features and are developed to keep pace with technical innovations on the machines.

The wide TWIN or Extra Large tyres reduce soil compaction and improves the soil structure – aiding better plant establishment and water penetration.
Ordinary tyres with high air pressure cause track formations and soil compaction that prevents the plant from developing its root system and the water from penetrating.  

More efficient machines utilization

Today’s efficient machines must be utilized during the complete season. Equipped with these tyres, work can be started earlier in springtime and proceed longer into the autumn, without ground damage, even in severe conditions.

Tubeless design

Most of the TWIN e EXTRA LARGE tyres are tubeless. This eliminates the risk of tube explosions and expensive downtime. This also means that you will be able to drive with low inflation pressure.

Prolonged lifetime

They have a gentle ground contact, which means less wear and a longer life. Compared with a standard tyre, these tyres can last 2–3 times longer.

Complete wheels

TWIN tyres are mostly delivered as complete wheel assemblies, matched to the machine or implement, or special customer requirements.

Tyre economy

Sound tyre economy comes from regular maintenance, operational care and a correct inflation pressure.

Rolling resistance and rut formation

The power needed to move a wheel over the ground is called rolling resistance.
The rolling resistance increases heavily if the wheel is pressed through the ground surface. Thanks to the width and their low air pressures, the TWIN e EXTRA LARGE tyres operate on top of rather than penetrating the ground surface. Power, fuel and time are saved with a low rolling resistance tyre, and rut formation and soil compaction are also minimized.

Pull force

A wide tyre and low inflation pressure increases the contact area. The pull force is therefore transmitted without unnecessary slippage, rut formation or soil compaction.

Slippage

Low inflation pressure increases the tyre contact area compared to high inflation pressure, reducing slippage.
Less slippage decreases the fuel consumption, gives better output and less soil damage.

Load-carrying capacity

It is the air that carries the load. Depending on the weight and the load of the machine, the inflation pressure and size of the tyre can be decided. The load-carrying capacity on wet and soft ground increases a lot with large tyres and a low inflation pressure. Follow the recommendations in this book regarding inflation pressure and load capacity.

Comfort

Low inflation pressure makes the tyre soft and flexible and able to "absorb" the bumps on the road. This makes the ride more soft and comfortable for the operator.

Wear and tear

The level of wear and tear will vary with the inflation pressure and the ground conditions.
A simple rule of thumb; soft tyres on soft and/or uneven ground, hard tyres on hard ground.
Examine the tyres and locate the worn areas. If the tyre tread is worn out on the shoulders, the tyre usually has too low an inflation pressure. When it is worn in the middle, the inflation pressure is too high.

Tyre shipment pressure

All wheels assembly by Trelleborg are inflated to a shipment pressure. Therefore, always adjust the pressure to a suitable service pressure according to the technical data tables.


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