Light yet strong
A passion for steel and cycling led employees from thyssenkrupp Steel to develop a new product: a racing bike made from steel. steelworks is light and quick – and ideal for long distances.
The bike passed the acid test with flying colors: In June six riders from thyssenkrupp Steel set out on a 1,000 km tour of Germany on steelworks, the first racing bike produced by thyssenkrupp Steel. They rode from Duisburg via Cologne to Lockweiler in the Saarland region and back via Belgium and Amsterdam. Ralf Stegmeyer was part of the team. “It was a great feeling,” he says, looking back. “steelworks met our expectations on the road in full. It’s a very comfortable, high-performance racing bike ideal for long distances.”
Ralf Stegmeyer is a passionate cyclist – and research & development engineer at thyssenkrupp Steel. His duties include developing application concepts for new steel technologies. Since 2017 he has been working on the steelworks designer racing bike. The goal: A lightweight, yet stable and durable racing bike for ambitious hobby cyclists.
“We started with a really simple question,” says Jia-Uei Chan, leader of the steelworks project. “Why are so few racing bikes made from steel?” After all, the material is ideally suited for bicycle frames thanks to its strength, stiffness and flexibility. One obstacle is the almost always identical appearance of conventional steel frames made from round tubes. Another is steel’s higher specific weight in comparison with, say, aluminum or carbon.
“So we needed to find a method that enabled us to use small, free-form cross-sections and develop a design that permitted the efficient transmission of forces,” says Jia-Uei Chan.
Virtually invisible welds
The classic deep drawing process, in which steel is mechanically pressed into a die, proved a suitable method. In this way the two halves of the steelworks frame are made from dual-phase steel just 0.7 millimeters thick. The halves are then welded together using a high-tech laser welding process which requires no filler, is extremely precise and results in virtually invisible welds. “This half-shell technology, which is otherwise primarily used in the automotive industry, ensures we achieve consistent high-end quality in the production of the bike frames,” says Chan.
Red Dot Design Award 2019 Best of the Best
“We have fashioned high-strength steel into a complex shape,” says Ralf Stegmeyer. The bionic design, for which steelworks has already won the “Red Dot” international design prize this year, brings the advantages of the material to the road. “For example we achieve a bottom bracket stiffness of 160 N/mm – the top value among 745 racing bikes tested. This means that when pedaling, your strength is converted directly into acceleration,” says Stegmeyer. At the same time, the high flexibility of the saddle tube and the intrinsic damping properties of the material make for a fatigue-free, comfortable ride.
“steelworks demonstrates thyssenkrupp Steel’s materials expertise and engineering know-how,” says project leader Chan. And steelworks demonstrates another thing too: That a big company like thyssenkrupp Steel has also mastered agile methods. “We managed the project like a start-up with a very lean structure, flat hierarchies and short decision-making paths,” says Chan. And a great deal of passion. “We put everything into it,” says Chan. “The DNA of our steel can be found in every fiber of steelworks.”