Spindown
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🚲 Comprehensive Wheel Spin-Down Suite
Analyze rotational speed, individual turn latency, and dynamic power dissipation overlays.
1. Add a Test Run
2. Active Runs Summary
The system is designed to capture the exact decay profile of a bicycle wheel during a free-spinning deceleration test by recording single-pulse-per-revolution hardware timestamps. When the wheel enters a predefined speed window (such as 200 down to 50 RPM), the microcontroller measures the microseconds elapsed between consecutive triggers from a sensor. By utilizing a known or estimated moment of inertia value representing the wheel's mass distribution, the desktop dashboard translates these raw temporal data points into physical quantities. This enables side-by-side analysis of mechanical drag and aerodynamic resistance without the need for load cells or heavy laboratory test equipment.
The primary velocity graph plots real-time RPM against a continuous timeline, tracing the degradation curve of rotational speed. The time-delta graph tracks individual latency changes from one rotation to the next, plotting the precise millisecond cost of each consecutive turn to highlight mechanical inconsistencies or sticking points within the bearings. Finally, the instantaneous power loss chart displays mechanical energy dissipation in Watts. This is achieved by converting the RPM values into angular velocity, computing the drop in stored kinetic energy over the elapsed duration of each turn, and rendering a direct profile of how much energy the combined forces of air resistance and hub friction consume at any given moment.∏
By evaluating these three distinct curves simultaneously, different tire setups, inflation pressures, and bearing tolerances can be objectively verified. At high speeds, the power dissipation chart helps isolate the aerodynamic penalties of wider tire profiles or aggressive tread designs due to the square-law nature of fluid resistance. As velocity decreases and aerodynamic forces decay toward zero, the remaining flat baseline on the wattage and delta charts isolates the constant mechanical friction within the hub assembly. This allows users to pinpoint whether a rapid deceleration curve stems from external air resistance or structural hub binding caused by excessive axle preload or compressed quick-release systems.