Bicycle Tires and Microplastic Pollution
The Hidden Environmental Cost of Cycling
While cycling is widely celebrated for its environmental benefits, recent scientific research has uncovered an unexpected environmental impact that even the most eco-conscious cyclists might not be aware of: microplastic pollution from bicycle tire wear.
A groundbreaking 2025 study from the University of Bayreuth has quantified for the first time the amount of microplastic particles released by mountain bike tires during real-world usage. The findings reveal that while bicycle tires do contribute to microplastic pollution, the scale is dramatically different from what we see with motor vehicles.
The Science Behind Tire Wear
Every time a bicycle tire rolls across terrain, microscopic rubber particles are abraded from the tire surface through friction. These tiny fragments, measuring less than 5 millimeters in diameter, qualify as microplastics and are released directly into the environment where cycling occurs. Unlike car tire wear that primarily occurs on paved roads and gets washed into storm drains, bicycle tire wear often happens in natural settings like forests, parks, and mountain trails.
The University of Bayreuth researchers measured tire wear by weighing mountain bike tires before and after controlled riding sessions. Their results showed that mountain bike tires lose an average of 3.64 grams of rubber per 60 miles of off-road riding. While this might seem minimal, it represents millions of microscopic particles being deposited directly into natural ecosystems.
Putting the Numbers in Perspective
To understand the significance of these findings, it’s crucial to compare bicycle tire wear to other sources of microplastic pollution. Motor vehicle tires release approximately 11 grams of particles per 60 miles of driving, making them roughly three times more polluting per mile than bicycle tires. However, the key difference lies in where these particles end up.
Car tire wear particles typically fall onto asphalt and concrete surfaces, where they’re eventually washed into urban runoff systems. Bicycle tire wear, particularly from mountain biking, occurs directly in natural environments where the particles can immediately interact with soil organisms, plant roots, and local water systems.
Environmental Implications
The environmental impact of bicycle tire microplastics extends beyond their mere presence in natural settings. These rubber particles can affect soil chemistry, potentially altering pH levels and nutrient availability. Some studies suggest that microplastics can also serve as vectors for other pollutants, concentrating harmful chemicals from the environment and potentially transferring them through food webs.
The persistence of these particles is another concern. Unlike organic materials that decompose naturally, synthetic rubber compounds can remain in the environment for decades or even centuries. This means that popular mountain biking trails may be accumulating microplastic deposits over time, creating long-term environmental legacies.
Emerging Solutions
Recognizing the growing concern over tire wear pollution, innovative companies like The Tyre Collective are developing technologies to capture tire particles at their source. While their current focus is on motor vehicles, similar approaches could potentially be adapted for bicycles in the future.
For now, cyclists can minimize their environmental impact by maintaining proper tire pressure, which reduces rolling resistance and wear, and by choosing durable tire compounds that shed fewer particles. Additionally, supporting trail maintenance organizations helps ensure that natural areas can better absorb and process the environmental impacts of recreational activities.
The Bigger Picture
The discovery of microplastic pollution from bicycle tires doesn’t diminish cycling’s status as an environmentally friendly transportation option. Rather, it highlights the complexity of environmental impact assessment and the importance of comprehensive scientific research. Even our most sustainable activities have environmental footprints that deserve understanding and consideration.
As research continues to reveal the full scope of microplastic pollution, the cycling community has an opportunity to lead by example in addressing these challenges proactively. By acknowledging and working to minimize even minor environmental impacts, cyclists can maintain their position at the forefront of sustainable transportation while contributing to broader environmental protection efforts.