In recent years, cheating behavior in various professional competitions is no longer limited to traditional drug doping, but has shown an endless stream of new methods. From setting physical traps such as nails on the track to more covert technical cheating and installing motors in the wheels and hubs in professional cycling competitions. With the rapid development of bicycle transmission systems towards electronicization, the core components of high-end bicycles——Wireless transmissions have also become a new target for hacker attacks. Hackers have started using technological means to attempt to gain an unfair competitive advantage by manipulating these transmissions, further exacerbating the challenge of fair competition in professional cycling races.

two thousand and twenty-fourTour de France bicycle race

The wireless transmission system of bicycles, as an important innovation in bicycle transmission technology, has attracted much attention in the bicycle industry in recent years. A wireless transmission system is a system that controls bicycle shifting through electronic signals rather than traditional mechanical cables. It utilizes advanced electronic technology and wireless communication protocols to achieve wireless, precise, and convenient variable speed operation. Compared to traditional mechanical transmission systems, it reduces chain jumping or jamming, providing a more precise shifting experience. Electronic transmission can be completed in an instant, providing faster response time. This precise control ensures that shifting can be completed quickly and accurately even under the most intense riding conditions. Moreover, due to the lack of mechanical cables, this system will not be affected in performance by weather, dirt, or wear and tear.

However, wireless transmission systems also face significant safety issues that cannot be ignored. Researchers have found through experiments that hackers can use software defined radio and antennas to intercept the target rider's gear shifting signals, and replay these signals at critical moments of the race to control the target bicycle's gear shifting. They can also forge signals to accidentally shift or fully lock the transmission when not needed. This type of attack can be carried out from 10 meters away, so hackers can interfere with the target driver without being detected. If users do not download the latest firmware patches in a timely manner, they may be remotely controlled by hackers, resulting in unexpected gear shifts or complete locking of the transmission on the track, thereby changing the race results and even causing injury accidents.

shimano Di2Wireless transmission components and hacker toolkit for researchers

In 2024UsenixAt the security seminar, researchers from the University of California, San Diego and Northeastern University showcased a hacking technique targeting the Shimano wireless transmission system. This technology utilizes hundreds of dollars worth of hardware equipment, including software defined radios, antennas, and laptops, to remotely control the target bicycle gearbox by intercepting and forging gear shift signals. Ximano'sDi2The wireless transmission system is one of the well-known products in the market. Since its launch in 2009, it has undergone continuous iterations and upgrades, and has now developed into its fourth generation. The Ximano Di2 wireless transmission system, with its excellent performance and reliability, occupies an important position in the high-end bicycle market. Many professional riders and cycling enthusiasts choose bicycles equipped with the Ximano Di2 system to participate in races or for long-distance cycling.

Faced with this security vulnerability, Ximano quickly responded and collaborated with the research team to develop a new firmware update to enhance the security of the Di2 wireless transmission system. Users can update the firmware themselves through the application to improve the system's protection capabilities.

This hacking technique reveals the security challenges of modern wireless devices. As more and more devices become networked and wireless, similar security vulnerabilities and attack methods need to be widely concerned and taken seriously. While enjoying the convenience brought by smart devices, the network security issues behind them must also be highly valued. Through continuous technological innovation, strengthening security design, enhancing user awareness, and improving laws and regulations, we aim to build a safer and more reliable environment for the use of smart devices.