E-bikes are a cost-effective, environmentally friendly way to make long commutes. To meet expectations for lighter, more battery-efficient e-bikes, two-wheeler brands look to lightweight drive units by replacing metal gears with robust plastic alternatives. Yet, widely-used plastic materials for gears aren’t reliable in demanding electric gearmotor applications. With its outstanding wear performance, fatigue resistance and processing capabilities, Envalior’s Stanyl® PA46 enables manufacturers to confidently replace metal gears for high-stress applications.   

E-bikes are key to decongesting crowded city roads and reducing air pollution. In addition to being more affordable than cars or motorbikes, next-generation e-bikes can travel more than 100 miles on a single battery charge. As a result, the global market for this technology is expected to be worth nearly $55 billion USD by 2027.  

Challenges you need to overcome when using plastics

Advancing e-bike drive unit designs is critical to meeting consumer expectations for lightweight e-bikes capable of travelling faster and covering longer distances. To extend e-bike driving ranges and improve their look and feel, drive unit manufacturers are reducing the size of these devices and replacing metal components such as gears with high-strength plastic ones.

Although plastic is more cost-effective to process than metal, material solutions for drive unit gears need to withstand high torque levels that result from commuters travelling faster, longer or over difficult terrain. These parts also need to be thin and small enough to fit into compact designs and improve rider experiences by generating low noise during operation.

Polyamide 66 and polyoxymethylene (POM) are popular material solutions for gears. However, higher torque levels cause gear teeth made from these plastics to wear out faster – which can cause drive units to malfunction. Polyetheretherketone (PEEK) demonstrates outstanding durability, however it is expensive and requires high-temperature processing. To drive more business from e-bike drive unit manufacturers, gears suppliers need to select a plastic that balances durability, design freedom and cost requirements.

Helping you make a gear with best-in-class mechanical performance and wear resistance

Gear manufacturers worldwide leverage Envalior’s Stanyl® PA46 to meet customer demand for reliable, cost-effective gears components optimized for compact designs and high mechanical loads. The material achieves best-in-class wear performance and fatigue resistance – often without the use of expensive additives – and offers:

• 20-50% higher torque capability compared to PA66 and POM
• Durability similar to carbon fiber filler-reinforced alternatives
• Significant cost savings compared to PEEK
• Space savings of up to 25% – without compromising part durability
• High crystallinity and flow properties ideal for fast-paced injection molding processing
• Grades optimized for non-lubricated conditions
• Potential to improve noise, vibration and harshness characteristics
• Proven performance with over 100 million gears made from Stanyl PA46 each year

Beyond supplying materials, Envalior provides comprehensive support to help manufacturers deliver high-quality products faster. Our state-of-the art computer-aided engineering and gear testing capabilities predict the short- and long-term reliability performance of materials. This helps suppliers reduce the number of design iterations needed – resulting in shorter development times and lower costs.

As e-bike producers look to adopt lower carbon solutions, our EcoPaXX PA410 material enables gear suppliers to offer high-strength components that are 70% bio-based. Our team is also developing a complete portfolio of fully bio-based or recycled materials for launch in 2030.

Envalior partners with industry-leading e-bike brands on a mission to empower more commuters to take advantage of reliable clean-energy transportation. Our high-performance materials, coupled with our comprehensive gear drive application expertise, enables our customers to elevate their strategies for bringing lighter, faster, safer and greener two-wheelers to market.