Hankook has announced the expansion of its successful SmartFlex line of truck tires with two new treads, the SmartFlex AH51 for the steering axle and the SmartFlex DH51 for the driving axle. The company claims a considerable increase in mileage performance for both new tire patterns: 15% for the steering axle and 20% for the driving axle.
“Hankook truck and bus tires have long been in the premium category globally and have therefore been used for some time now by many well-known and leading vehicle manufacturers as original equipment worldwide,” said Sanghoon Lee, president of Hankook Tire Europe. “As a company, we place a high value on the sustainability of our products, and therefore our newly developed smart treads fulfill our aspirations for ensuring sustainable and futureproof tires, and of course also in conjunction with significantly increased customer benefits.”
In the development of both tires, the company’s design engineers used the Hankook SmartLife concept, which is claimed to place a specific focus on sustainability. Notable is a requirement for the products to always offer the highest possible performance from the first to the last millimeter of tread depth.
The base compound of both patterns of AH51 and DH51 was, says Hankook, designed for efficiency. To this end, an increase in the proportion of low-damping materials contributes to a reduction of principle viscoelastic power loss throughout the tread, improving efficiency.
The sidewall compounds were also freshly developed, with an emphasis on increased resistance to crack formation and material fatigue. The DH51 tire also features distinctive notch-tough tread compounds, where high-performance resins are used to improve durability through the use of increased-molecular-weight polymers.
Hankook adds that its IMS (Innovative Mixing System) is used to ensure an even distribution of carbon black particles and rubber molecules within the compounds. In combination with the extension of the mixing times at lower temperatures, a significant increase in the bonding rate between the carbon black and rubber molecules can be achieved. As a result, the tires generate less heat during operation.
The company notes that its SCCT (Stiffness Control Contour Theory) design technology, used across its SmartFlex products, ensures that the internal pressure distribution is as evenly balanced as possible depending on the application. This results in greater stability and less movement in the tire casing during use, which leads to high durability of the carcasses and good retreadability.
For the belt plies and the carcass itself, the AH51 and DH51 use high-strength steel cord materials. Together with the SCCT contour, this is claimed to result in a consistent contact patch for even wear, as well as improved traction and braking performance.
3D sipes with self-regenerating tread features are also incorporated into the AH51 and DH51 treads, which emerge after wear of between 40% and 70% in the tread pattern. The task of these ‘regenerating’ grooves is to lock the tread blocks together and aid overall tread stability, which benefits mileage. So-called ‘hidden grooves’ appear at a wear level of around 70% and ensure continued high traction and wet grip even in wet conditions until the tread is completely worn out.
The wide tread blocks of the AH51, which can also be used as an all-position tire, are equipped with additional supports (TWES – Tread Wear Equalised Stepper) in the outer grooves, which increase the tread stiffness in conjunction with the broad tire shoulder ribs. The DH51 has a wider contact patch than its predecessor, which increases traction while improving mileage and rolling resistance.
Finally, special sipes on the shoulder blocks, which naturally are under stress on drive axle tires, help to reduce cracking even during peak loads. In addition, they support tread drainage to further improve traction performance.