The story of the recently launched Alliance AGRI STAR II started after Agritechnica 2017: Inspired by this leading agricultural fair, engineers of Alliance Tire Group spent almost 24 months developing a tractor tire to satisfy all modern demands in the segment. During the first phase of development, a thorough research across several geographic regions was conducted to identify the main requirements of farmers and tire dealers. This research resulted in the definition of key deliverables:
- high value for money,
- massive traction throughout the whole tire life,
- outstanding durability,
- top performance also during on-road operations,
- superior braking properties,
- excellent self-cleaning characteristics.
In the second phase, 3D model concepts of this tire were shown to the focus groups of farmers and dealers to get their feedback on the proposed design and construction of the new AGRI STAR II. Following their suggestions, some modifications were made, including broader shoulders, a special lug nose and lug wall contour, as well as an optimised number of lugs.
Extraordinary high quality materials and components were chosen in the design process. PET, Poly Ethylene Terephthalate, acts as the reinforcing backbone of AGRI STAR II. Instead of the frequently used nylon, Polyester was selected as very durable material for carcass and belt fabrics. It ensures that the tires ‘are still round’ and keep their shape even after years of challenging operations. It also helps to avoid the temporary deformation in the tread which may occur with nylon carcasses when parking the tractor overnight after demanding operations with resulting heat build-up. Keeping the tire in its original shape at all times further adds to a perfect on-road performance and reliable traction throughout the tire’s whole lifetime.
In the field and on the road
In agriculture of today, be it farms or contract businesses, road transfers make for a growing part of daily operations. Engineers at Alliance accepted the challenge of adjusting tractor tires to this growing demand by providing solutions for more driving comfort, less noise and vibration, high speed, low tire wear as well as good steering and breaking performance – all this in addition to delivering top results in the field.
More rubber volume was added to the central part of the overlapping lugs. This additional rubber provides more stiffness and lower wear on asphalt whilst further improving the driving experience on roads. The D speed rating – 65 km/h – is yet another non-standard feature used by engineers to improve the on-road performance of tractors and the driving experiences of operators. Design features also ensure the excellent self-cleaning abilities of this tire which are equally important during in-field operations – and when leaving the fields without making a mess on public roads.
The secret of the Stratified Layer Technology (SLT)
The AGRI STAR II comes with several particular construction characteristics. First of all, there is the unique Stratified Layer Technology (SLT) that was exclusively developed by the engineers of Alliance Tire Group.
The unique feature of the SLT technology is its ability to give ‘a second life’ to a tire after the initial 40% of wear, thus also ensuring perfect traction for the second half of the tire’s lifetime. When the tire is still new, powerful traction is delivered by the high non-skid depth (NSD) of the lugs. After 40% wear, when the top layer of the lugs is completely gone, the bottom layer comes into action. At this stage, lugs change their geometry and, due to the multi-angle profile of the bottom layer, lugs become broader and more curved. The now reduced NSD is fully compensated by a larger tire-to-ground contact area: with their multiple angles, lugs powerfully push the mud away, ensuring perfect traction yet again.
This change of lug geometry is one of the secrets behind the extraordinary performance and durability of the AGRI STAR II.
And there is more: Dual step tie bars prevent lug shuffling and act as mud-breakers, thus further adding to the excellent self-cleaning characteristics. In conjunction with features such as wider tread width, overlapping central lugs, special nose angles and a smooth profile of the lugs, the AGRI STAR II is a synonym for truly impressive performance, dimensional stability and top durability.