Hinnerk Kaiser

How challenging was it to integrate recycled materials without compromising safety and performance?

The requirement to integrate a high proportion of recycled materials into the product posed additional challenges for development. When selecting materials, we carefully examined whether and to what extent there were conflicts of interest with the required performance criteria. We deliberately chose materials that did not compromise these criteria, or we were able to develop appropriate compensation measures. For example, material from recycled old tires (reclaim) can be used in casing components where it has no impact on performance.

In addition to outstanding grip, the innovative tread pattern design enables quiet running noise. What significance does this have in terms of electromobility?

Rolling noise plays an important role in electric buses, as there is no engine noise and tire noise is more noticeable. The Conti Urban HA 5 NXT has a specially developed tread concept with so-called “pitching”: The length of the tread blocks varies, and they are arranged in such a way that the tire noise generated is distributed over a wide frequency spectrum. This makes it pleasant to the human ear. The tire achieves the best rating (class A) on the EU label for external rolling noise.

The tire's durability has been increased by 15 percent. How important is abrasion in urban driving scenarios?

High mileage was one of the key development goals for the Conti Urban HA 5 NXT. This was achieved through a new tread compound in combination with a specially tuned tread pattern. The decisive factor here was not an increase in the amount of material, but rather the targeted optimization of the abrasion rate. This results in fewer abrasion particles per kilometer, a particularly important environmental aspect in urban use with frequent starting and braking. In addition, the robust tread design contributes to durability and is optimally designed for the high starting torques of electric buses. A reinforced sidewall offers curb protection, and wear indicators allow for easy checking of the wear condition.

Rolling resistance has been reduced by 25 percent. What material innovations made this progress possible?

We took all relevant components of the tire into account when optimizing rolling resistance. The newly developed tread compound plays a key role in this, as does the combination of an optimized tire contour and adapted tread design stiffness. The aim was to minimize the tire's hysteresis – energy losses caused by the conversion of material deformation into heat. A “cool-running” tire always has better rolling resistance. That's why all components of the Conti Urban HA 5 NXT were designed precisely with this goal in mind.

To what extent can the new tire contribute to extending the range of electric city buses?

The improved rolling resistance of the Conti Urban HA 5 NXT has a direct impact on the range of electric city buses. Tests we have conducted together with manufacturers show a range extension of up to 15 percent, depending on the application. This illustrates the decisive contribution that optimized tire technology can make, especially for electric vehicles.

How much does the special tire design contribute to the performance of electric buses?

The new tire design offers several key advantages for electric bus applications. The specially developed tread design reduces rolling resistance, which both increases range and lowers operating costs (total cost of ownership, TCO). The innovative pitch variation – i.e., the targeted variation in tread block lengths – ensures a reduced noise level, which is particularly important for the quiet operation of electric buses. In addition, the design is tailored to the higher drive torques of electric buses. The robust construction ensures excellent abrasion performance, even in demanding urban traffic.

Continental has been balancing cost efficiency and sustainability for years through innovative solutions. Does this also apply to the new Conti Urban?

The Conti Urban HA 5 NXT is an excellent example of how cost efficiency and sustainability can be combined through intelligent tire technology. The significantly reduced rolling resistance noticeably lowers our customers' operating costs. At the same time, with lower CO₂ emissions and a high proportion of recyclable and sustainable materials, we are making an important contribution to environmental protection – both in the manufacture and during the use of the tire.

Why is the Conti Urban HA 5 NXT a good choice for vehicle manufacturers in both the original equipment and replacement tire business for bus fleets?

We are particularly proud of the Conti Urban HA 5 NXT, as it combines numerous improvements that are of great importance for both the original equipment and replacement business for bus fleets. With significantly reduced rolling resistance, increased mileage, and a high proportion of renewable, recycled, and ISCC PLUS^* *-certified materials, the tire offers our customers tangible cost advantages while also contributing significantly to Continental's sustainability strategy. Electric buses in particular benefit from the robust product design and the resulting low noise level. With the Conti Urban HA 5 NXT, we are well equipped to meet current and future regulatory requirements.

^{* The share may vary between 55% up to 60%. The Conti Urban HA 5 NXT contains 32%-34% recycled and renewable materials, including recycled rubber and natural rubber. Furthermore, Continental sourced 22%-26% of ISCC PLUS-certified materials via the mass balance approach from bio, bio-circular, and/or circular feedstock.}

^{** The ISCC PLUS standard supports the transition to a circular economy and bioeconomy. This voluntary certification standard validates the sustainability characteristics of alternative feedstocks throughout the entire supply chain, from origin to end consumer}