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Further Validation of Equations for Motorcycle Lean on a Curve

Journal Article
ISSN: 2327-5626, e-ISSN: 2327-5634
Published April 03, 2018 by SAE International in United States
Further Validation of Equations for Motorcycle Lean on a Curve
Citation: Rose, N., Carter, N., and Smith, C., "Further Validation of Equations for Motorcycle Lean on a Curve," SAE Int. J. Trans. Safety 6(3):173-191, 2018,
Language: English


Previous studies have reported and validated equations for calculating the lean angle required for a motorcycle and rider to traverse a curved path at a particular speed. In 2015, Carter, Rose, and Pentecost reported physical testing with motorcycles traversing curved paths on an oval track on a pre-marked range in a relatively level parking lot. Several trends emerged in this study. First, while theoretical lean angle equations prescribe a single lean angle for a given lateral acceleration, there was considerable scatter in the real-world lean angles employed by motorcyclists for any given lateral acceleration level. Second, the actual lean angle was nearly always greater than the theoretical lean angle.
This prior study was limited in that it only examined the motorcycle lean angle at the apex of the curves. The research reported here extends the previous study by examining the accuracy of the lean angle formulas throughout the curves. The degree to which these equations can be used to model the development of lean as the rider enters a curve is evaluated. The prior study was also limited in that it only examined maneuvers on an oval track in a flat parking lot. The current study examines the accuracy of the theoretical lean angle formulas on a mountainous highway with curves of varying radius and changing banking and slope. The real-world data presented in this study are also utilized in conjunction with the lean angle formula to examine the interplay between the geometry of a curve, the motorcycle speed, and the rider’s skill level.