reflex

What it does

REFLEX is an active safety system for road bikes, addressing the critical issue of rear-wheel lock-up, skidding, and fishtailing during emergency braking.

Your inspiration

The decision to solve this problem stems from a critical safety hazard in road cycling: road bikes can reach high speeds, and during emergency braking or on poor road surfaces, the rider's center of gravity shifts forward. This shift reduces the rear-wheel load, making it extremely prone to locking up and skidding, which can lead to side-slips, fishtailing, or crashes. The idea for the solution came from the need to fill this technological gap with an assistive system that actively intervenes to prevent rear-wheel lock-up, thus providing a more reliable safety net for cyclists.

How it works

Our design, REFLEX, is an intelligent "Anti-lock Braking System" (ABS) for a bicycle. It operates based on three core principles: Sensing: The system is equipped with speed sensors on both the front and rear wheels. These components constantly track the speed difference between the two wheels and detect the bike's posture, such as tilting or sharp deceleration. Control: When you brake hard, if the system "senses" that the rear wheel is about to lock up (i.e., its speed drops much faster than the front wheel's), a lightweight, high-response rear brake pressure modulation unit instantly takes action. Communication & Feedback: Uniquely, the system doesn't just work silently; it "communicates" with the rider. A micro-vibrator is built into the rear brake lever.

Design process

The team first identifies the core pain point of road cycling during emergency braking—the risk of losing control due to rear-wheel lock-up. The initial concept is to develop a miniature, lightweight "ABS for bikes." The team miniaturizes the validated components and mounts them onto a test bicycle for the first time. The enclosures would be 3D printed for rapid iteration of shape and mounting solutions. The system might still look clunky with exposed wires, but it's a complete system that can be tested on a real road. The prototype at this stage looks much closer to the final product. The team would design a custom PCB to replace the bulky development board, significantly reducing the control module's size. The enclosure design would be more focused on aerodynamics and aesthetics, aiming for seamless integration. The team might collaborate with a brake manufacturer to try integrating the module directly into the brake caliper or lever.

How it is different

The REFLEX design's uniqueness, which sets it apart from other traditional ABS systems, lies in two main areas: Innovative "Perceive-Feedback-Learn" Loop: Beyond just preventing lock-ups, the system introduces a unique haptic feedback system in the brake lever. This is more than a simple alarm; it's an extension of the rider's own senses. Through vibration feedback, the system helps the rider feel the critical state of the rear-wheel's grip, assisting them in improving their braking skills through practice. This feature not only enhances safety during a single ride but also helps the rider become better over the long term—an educational and skill-enhancing function not found in typical ABS.

Future plans

The goal is for the system to become a standard safety feature in mid-to-high-end road bikes, significantly enhancing safety for riders of all skill levels. The design has the potential to reduce accidents that are caused by emergency braking errors and adverse road conditions. Enhancing Rider Skill: The "Perceive-Feedback-Learn" loop is intended to assist riders in improving their personal braking techniques over time. The technology is designed to be adaptable. With modifications, it could be applied to other types of bicycles in the future, such as e-bikes and commuter bikes.

Awards