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Decelerations of Capsized Motorcycles - An Update
ISSN: 0148-7191, e-ISSN: 2688-3627
Published March 29, 2022 by SAE International in United States
Annotation ability available
Many motorcycle crashes involve the motorcycle capsizing, impacting the ground, and sliding on the road surface. When performing speed calculations, the energy or speed loss for the ground impact and sliding phases may need to be calculated. To perform these calculations, the reconstructionist will typically determine the slide distance based on the physical evidence and then apply a range of decelerations over that distance based on test data in the literature. Decelerations can be selected for motorcycles with similar characteristics (crash bars, panniers, fairings, etc.) sliding on similar surfaces (asphalt, concrete, dirt, gravel, etc.).
This approach is adequate but sometimes results in a wide range due to the variability in reported decelerations in prior studies. It could be helpful to narrow the likely range of decelerations, and thus, the speed range. Many past studies, however, describe their tests with inadequate detail to parse out precisely what factors were most influential in producing the reported decelerations. The present study reports four additional motorcycle drop and slide tests, attempting in the process to lay out a model for how future tests could be reported such that influential factors could be identified. In addition, this test series included a motorcycle with crash bars. This motorcycle was tested twice with the crash bars. Then the crash bars were removed, and the motorcycle was tested again. These tests involved the motorcycle experiencing more significant impacts with the ground than prior tests involving motorcycles with crash bars.
CitationRose, N., Palmer, J., Smith, C., Carter, N. et al., "Decelerations of Capsized Motorcycles - An Update," SAE Technical Paper 2022-01-0823, 2022, https://doi.org/10.4271/2022-01-0823.
- Lambourn , R. The Calculation of Motorcycle Speeds from Sliding Distances SAE Technical Paper 910125 1991 https://doi.org/10.4271/910125
- Baxter , A.T. Motorcycle Crash Investigation Jacksonville, FL Institute of Police Technology and Management 2017 978-1-934807-18-7
- Hague , D. Calculation of Speed from Motorcycle Slide Marks Impact: The Journal of the Institute of Traffic Accident Investigators Spring 2004
- Wood , D.P. , Alliot , R. , Glynn , C. , Simms , C.K. et al. Confidence Limits for Motorcycle Speed from Slide Distance Proc. IMechE Vol. 222, Part D: J. Automobile Engineering 2008
- Walsh , D.G. , Wood , D.P. , Alliot , R. , Glynn , C. , Simms , C.K. Motorcycle Capsize Mechanisms and Confidence Limits for Motorcycle Capsize Speeds from Slide/Bounce Distance 18th EVU Conference Hinckley, UK 2009
- DiTallo , M. et al. 3 Different Methodologies for Determining the Drag Factor for Motorcycles Sliding on Their Sides Collision: The International Compendium for Crash Research 12 1 September 2017
- Bartlett , W. , Baxter , A. , and Robar , N. Motorcycle Slide-to-Stop Tests: IPTM Data through 2006 Accident Investigation Quarterly Spring 2007 1082-6521
- Peck , L. , Focha , W. , and Gloekler , T. Motorcycle Sliding Friction for Accident Investigation Proceedings of the 10th International Motorcycle Conference Institute for Motorcycle Safety, Essen, Germany 62 78 2014
- Petroskey , K. , Funk , C. , and Tibavinsky , I.A. Validation of Telemetry Data Acquisition Using GoPro Cameras SAE Technical Paper 2020-01-0875 2020 https://doi.org/10.4271/2020-01-0875
- SAE International Surface Vehicle Recommended Practice Jul. 2007