Stefan Dengler, Managing Director of SDS Systemtechnik, isn’t the sort of person you meet every day. He is kind, knowledgeable, courteous and a true family man. Not traits uncommon in the retreading industry, but Dengler has a certain quality that immediately makes you warm to him. Our conversation starts with an explanation that growth has never really been his central objective for the business, even as he presides over a genuinely-industry leading operation. The company’s focus, he explains, is engineering, technical development, and solving practical problems for customers. Growth has come as a handy byproduct of such dedication.
Dedication, Care and Service
“I do not want to say nobody else in the industry is growing, but if you look back over the last few years, growth has not been the main issue,” Dengler said. “It was never my intention simply to grow. I like what I am doing. I am somehow in love with the machines, the technology, and the solutions. If we can grow by building machines or developing new projects, then I like that. But growth for its own sake is not my business goal.”
This approach has produced a stable business over many years. Dengler describes SDS as a company that has maintained consistency by focusing on its core technical strengths, rather than chasing volume or diversification for its own sake. However, market conditions vary significantly by region. North America, he noted, remains difficult: “There is money, but nobody is spending it.” According to Dengler, the issue is not a lack of activity in the market, but the uncertainty surrounding investment decisions. He believes many companies are waiting to see how the political and economic landscape develops before committing to new capital expenditure. “They are just waiting,” he explained. “The situation is so unstable. They do not know what is coming tomorrow. This makes people nervous. Some will say that if we do not do it this year, even with the risk of paying more taxes, we should wait two or three more years.”
Despite the current slowdown, Dengler sees a clear shift in the North American market’s attitude towards automation. Ten years ago, he recalled, American retreaders questioned the need for conveyor systems and other automated solutions. Today, those same customers are increasingly asking what more can be automated. “They used to say, ‘We have operators,’” Dengler said. “Today, they say, ‘We have no skilled labour.’ That is a change, and this is where we can participate with our partners.”
China, by contrast, continues to develop, particularly in new tyre production. Dengler acknowledged that Chinese manufacturers are becoming more capable in many areas, but he remains confident that high-quality shearography, of the type developed, made and maintained by SDS, is not easily replicated. “It is possible,” he said, but that costs so much time, effort and money that it “would not pay off”. The way to develop a reasonable solution with the technical know-how behind it is not just to build a good machine or make attractive software. It is the combination of knowledge in optics, software, and hardware, along with the necessary technical tricks, to bring everything together at a level that works well enough. Shearography is not just a “nice-to-have” but an indispensable part of the manufacturing process for new tyres.
Dengler also discusses its use in retreading. He makes it clear that retreading can indeed be carried out without shearography, but notes that this places significantly higher demands on the operators performing incoming inspection and substantially increases the risk of defects.
New demands are also emerging from the market, particularly around traceability and the need to capture complete sidewall information from tyres. Dengler said SDS already has relevant know-how through its other applications, including laser marking. However, he is cautious about moving beyond the company’s core competence. In areas such as sidewall data collection and digitalisation, SDS is increasingly looking at cooperation rather than direct expansion.
“I have to be careful that SDS focuses on its core business,” Dengler explained. “I see REGOM as a very professional company in this area. There are different approaches in the market, and many companies offer valuable AI expertise. What stands out to me about REGOM is that they come from the application side and have deep practical experience in the industry. This perspective fits very well with our needs. That is why it makes sense for us to work with REGOM, whether through hardware supply, interfaces, or applications in tyre collection.
For Dengler, collaboration is essential, provided each company understands its strengths and limitations. SDS, he said, has built its position by focusing on machines, after-sales support, maintainability, and long-term customer relationships. “SDS has always paid a lot of attention to the machines we have in the field,” he said. “After-sales support and maintainability are very important. We can upgrade machines. Even our machine number one is still running in Argentina today. It was previously at Reiff in Reutlingen, was refurbished twice, and is now operating in Argentina. That is what we are proud of.”
This commitment to service also shapes SDS’s approach to older machines. Rather than automatically recommending replacements for older machines in the field, SDS first assesses whether the machine’s capacity still meets the customer’s requirements.
“Even if a machine is around 20 years old,” he said. “The first question is whether the capacity is enough. If the capacity is enough, there is no reason to replace the machine. We can upgrade it with the latest measuring technology; Windows 11, new optical systems, and new cables, making it as good as new. A new machine is faster and allows more automation, but if the existing capacity is enough, then we maintain the machine.” Dengler believes this service philosophy is one of SDS’s strongest commercial advantages. Existing machines in the field, he said, are the company’s best sales representatives.
SDS is also preparing for generational transition. Dengler said one of his main priorities is ensuring the business is ready for the next generation. His daughter Mara is already deeply involved in the commercial side of the company, including administration and purchasing, while her brother Simon is contributing to the technical and software side.
One of the company’s key development projects is AI-based result validation. Dengler said the demand is particularly strong in the new tyre industry, where automated processes are already standard, and the introduction of shearography creates a need for continuous assessment of results.
“In retreading, there is typically an operator standing with the machine,” Dengler said. “AI can help, but the need is not the same as in the new tyre industry. In the new tyre industry, everything is automated, and then shearography comes in, and suddenly you need an operator all the time. In retreading, everyone knows that some casings are not acceptable. In new tyre production, 0% is not acceptable. So why should an operator stand in front of the machine for eight hours? That is where there is real demand for automated result validation.”
Dengler sees this as part of a wider process of preparing SDS for the future. “We have a good group of young people in SDS now, including on the mechanical construction side,” he said. “At the moment, I feel my major job is to prepare the company for the next generation.”
Succession is a challenge across much of the retreading sector, which remains heavily family-owned. Dengler considers himself fortunate that his children have chosen to continue the business. “I am really happy that my kids took the decision to continue what I was able to build with our customers,” he said.
On diversification, Dengler is clear that SDS has already explored other markets in the past, including aviation and composite materials, where shearography can also be used. However, the company ultimately concluded that its resources were best deployed in the tyre industry. “We tried to go into different markets,” he explained. “There are other materials where you use shearography, but at the end of the day we realised it makes much more sense, with the limited capacity we have, to focus on what we do best.”
That does not mean SDS is limited to a single product. In addition to shearography, laser marking is an important part of the business, and the company continues to invest in R&D, next-generation software, and related technologies. But its guiding principle remains focus.
“Our principle is to stay focused on what you know and what you can do,” Dengler concluded. “Do it better, do it faster, and save cost where you can.”
