Motorcycle Lean Angle Variation Around a Constant Radius Curve at Differing Speeds and Travel Paths with an Evaluation of Data Measurement Systems 2019-01-0437
Recent studies evaluating motorcycle lean angle have compared theoretical lean angle equations with real-world-tested motorcycle lean angles. These studies have considered several factors affecting lean angle, including the simplified assumptions made when calculating theoretical lean angles, the speed of the motorcycle around a curve, and the geometry of the roadway/curve. This study further evaluates motorcycle lean angle as a function of speed, but primarily focuses on the effects of different travel paths selected by the rider around the same constant radius curve. The testing incorporates nine passes around the same curve traveling three different paths at three incrementally increasing speeds. The real-world-tested lean angles were compared to the predicted calculated lean angles for each tested travel path based on the graphically reconstructed radius of curvature generated through 3-dimensional laser scans of the roadway and orthomosaic imagery via small Unmanned Aerial Vehicle (sUAV). The analyzed curve is a long sweeping constant radius curve with an approximate 670 ft-radius of curvature. This study also analyzed the variations in lean angle through the transient entrance of the curve, steady-state middle of the curve, and transient exit of the curve. The vehicle speeds and lean angles were obtained through three on-board data logging devices: Racelogic’s Video VBOX, Apex’s Speed Angle Data Logger with GPS and Lean Angle Measurement, and Harry’s Lap Timer Data Logging Application via iOS and an iPhone X. The accuracy and effectiveness of this data was compared and analyzed. The results of this testing empirically establish that at a given speed on a given curve, motorcycle lean angle can vary significantly depending on the travel path selected by the motorcyclist.
Ronny Wahba, Thomas Timbario, Jonathan Nelson, Fawzi Bayan, Dalton Jordan, Jonathan Swanson, Ashley Dunn