Sustainability ambitions are forcing the bicycle industry to rethink its reliance on aluminum and carbon fiber. At Taichung Bike Week 2025, exhibitors showcased a new generation of materials that promise performance and recyclability alike.
Eight years ago, the British daily The Guardian published photographer Chen Zixiang’s iconic image of a vast bike dump near the city of Xiamen. The tens of thousands of bicycles piled up were the result of a well-known bike-sharing provider’s bankruptcy just days earlier. Instead of selling or reusing the bikes, the entire fleet was scrapped. Zixiang captured the bikes rotting in the open air – drawing global attention to the dark side of the mobility transition. While the bicycle is seen as the most sustainable mode of transport, the drone image showed how the industry’s “green promise” can collapse through mass production and poor recycling concepts. Nowhere is this more evident than in materials, which explains why they have become a key focus of industry efforts in recent years.
Globally, aluminum, carbon and steel dominate bicycle production. Their environmental impacts are well documented: Germany’s Federal Environment Agency classifies bauxite – the main ore for aluminum – as risky due to ecological and human-rights concerns. Carbon, common in high-performance frames, is criticized for energy-intensive production and poor recyclability. Steel lasts longer and recycles more easily, but its manufacture consumes vast amounts of energy. The World Economic Forum estimates aluminum contributes about 3% of global CO2 emissions and steel around 7%. Carbon, though produced in smaller volumes, has the worst footprint per kilogram. The bicycle industry’s share may be small, but to improve sustainability, finding alternative or recyclable materials is essential.
This trend is clear in manufacturers’ sustainability reports. A life-cycle analysis by Taiwanese producer Giant showed nearly 70% of the 159 kg CO2e footprint of its aluminum Stance 29 1 came from raw materials. Another report revealed its carbon TCR road bike has a footprint of 274 kg CO2e, with 55.3% from materials. Finnish component maker Herrmans reported in 2023 that materials account for over 90% of its footprint. These figures are no surprise: before production, raw materials must already be mined or grown, creating a negative CO2 balance. Manufacturers are therefore working to improve their material mix – developing recycling solutions for aluminum, carbon and steel, while also testing alternatives.
The shift has become increasingly visible at recent tradeshows. Giant unveiled a children’s bike built from recycled carbon, while Riese & Müller presented the cargo bike “Carrie” with a frame made from 81% certified recycled aluminum. Trek and VP Components highlighted progress in low-carbon aluminum technology, and Brompton showcased rims produced from Hydro’s 100% post-consumer recycled alloy. Other examples are Igus, Chi-Tai Enterprise, Weber Fibertech and Lehvoss, which demonstrated thermoplastic composites designed for full recyclability. The same momentum will be on display at Taichung Bike Week, where exhibitors again put material innovation at the center of their sustainability agenda.
“Material innovation is a driving force for industry transformation and achieving low-carbon goals,” says Amy Shih, marketing director at Taiwanese component maker Nuvo. The company has been exploring “green carbon” composites, recycled carbon, post-consumer plastics from fishing nets and lightweight aluminum alloys. Its n+1 line embodies this approach, with the BC136 bottle cage as a showcase. Built from recycled nylon with over 50% fishing nets, it meets recycling standards and is designed for easy disassembly.
For Shih, the principle is clear: Performance and sustainability must be balanced at every stage of design. “As demand for eco-friendly, high-quality products grows, new materials will both improve performance and push the industry toward greener development,” she says.
“We believe material innovation is key to sustainability,” says Charles Lee, owner of Glory Wheel. The Taiwanese brand developed a recycled 6-series aluminum alloy using its own scrap mixed with new material. Though not identical to standard 6061, it works well for non-load-bearing parts. The ER75 Spacer is the first product using this alloy, producing just 0.0381 kg CO2e per unit – about 75% less than a typical spacer. For Lee, it’s about more than one part. “The bike industry has over 200 years of history. Every material shift – wood, steel, aluminum, carbon – has moved us forward. Now, with global carbon challenges, material innovation isn’t just about performance, it’s about building a more sustainable future.”
A third example comes from Lehvoss, a German specialist in high-performance polymers. The company is developing thermoplastic composites reinforced with recycled carbon fibers to combine technical performance with a smaller footprint. “We’re developing new materials using recycled carbon fibers, focusing on bike frames. The goal is to cut the carbon footprint,” says Eric Folz, senior market development manager.
At Taichung Bike Week, Lehvoss showcased a new generation of saddle materials that are 45% to 100% bio-based and reinforced with recycled fibers. Compared with the current PA12-CF15 standard, these compounds deliver superior properties and a much lower CO2 impact. Folz believes the sector is nearing a breakthrough. “It’s crucial to keep an eye on a bicycle’s global warming potential, including materials, recyclability and transport. End customers are becoming increasingly aware of the carbon footprint and the origin of parts.”
Taken together, these examples show how deeply material innovation has moved into the center of the bicycle industry’s sustainability agenda. From recycled aluminum alloys to bio-based thermoplastics, suppliers are proving that performance and environmental responsibility can go hand in hand. Challenges remain – scaling up production, securing scrap supplies, and convincing consumers to embrace new materials – but the trajectory is clear. The image of abandoned bikes in Xiamen once highlighted the industry’s contradictions; today, the push for circular materials is an attempt to ensure that bicycles live up to their role as a true symbol of sustainable mobility.