This book aims to provide the core concepts of motorcycle dynamics and illustrates their application in vehicle design to readers who have a serious interest in the subject and in particular to engineers with a career path in the powered two wheelers sector.
The book is best suited for readers with a background in mathematics and mechanics that is normally possessed by ﬁnal year undergraduate students in engineering.
Buy Hardcover ISBN: 979-12-200-9853-3
Buy Paperback ISBN: 979-12-200-9852-6
Table of Contents
Chapter 1: Motorcycle Design
The Motorcycle as a Vehicle. Brief history. Motorcycle systems. Frame. Engine. Transmission. Swinging arm. Front-end. Wheels. Brakes. Electrical. Bodywork. Accessories. Motorcycle Segments. Sport. Standard. Cruiser. Touring. Scrambler. Dual Sport. Dirt Bike. Scooter. Motorcycle industry. Market. Manufacturers. Regulations. Racing. Jobs within the industry. The Design Process. Virtual Prototyping. Tools for Design. Tools for Simulation. Testing. Human Factors. Rider Training. Motorcycle Simulators. Design Pillars. Safety. Performance. Sustainability. Powered two wheelers in the future.
Chapter 2: Fundamentals of Motorcycle Dynamics
Overview. Geometry. Degrees of freedom and coordinates. Angular velocity. Acceleration. Steering kinematics. Steady Cornering. Lateral acceleration. Roll angle. Steering response. Cornering dynamics. Roll dynamics. Capsize stability. Rider control. Counter-steering. Acceleration performance. Propulsion power. Tyre adherence. Tyre load. Rear wheel spinning. Wheeling. Maximum acceleration. The influence of speed. Braking. Rear braking. Front braking. Combined braking. The motorcycle performance envelope. Governing equations. Motorcycle pitching limits. Tyre friction ellipse. Tyre adherence limits. Performance envelope. The influence of speed.
Chapter 3: Tyres
Fundamentals. Structure. Designation. Forces and moments. Geometry. Contact patch. Compliance. Kinematics. The Bare Minimum Tyre Model. Linear model with saturation. The friction ellipse. The Brush Tyre Model. Longitudinal force. Sideslip force. Self-aligning torque. Camber force. Twist torque. Limitations. The Magic Formula Tyre model. The Ma- gic Formula. Pure longitudinal force. Pure lateral force. Combined longitudinal and lateral forces. Rolling resistance moment. Yaw torque. Overturning torque. Magic Formula versions. Transient models. Linear dynamic response. Other models.
Chapter 4: Powertrain
Power unit. Internal combustion engines. Electric motors and batteries. Hydrogen and fuel cells. Hybrid electric vehicles. Transmission. Clutch. Manual gearbox. Continuously variable transmission. Final drive. Driving Performance. Driving forces. Speed and torque conversion. Power balance. Energy efficiency. Pollution. Tackling emissions. Engine emissions legislation.
Chapter 5: Suspensions
Shock absorbers. Springs. Dampers. Front suspension. Telescopic fork. Leading link and trailing arm forks. Telelever. Hub-centre steering. Rear suspension. Swinging arm. Four bar linkage. Suspension analysis. Suspension equivalence. Telescopic fork. Swinging arm. Motorcycle trim. Static. Acceleration. Front braking. Rear braking. Combined braking. Chassis pitch and heave.
Chapter 6: Response to road excitation
Road characterisation. Frequency decomposition. Random roads. Vehicle performance indices. Comfort. Roadholding. In-plane vibration modes. Heave. Pitch. Wheel hops. Suspension performance. The half-motorcycle model. Response to a road step input. Frequency response functions. Response to random excitation. Optimisation of suspension stiffness and damping. Non-linear analysis. Response to a road step input. Response to random excitation. Full motorcycle analysis. Five degree of freedom model. Modal coupling. Frequency response functions. Wheelbase filtering. Response to random excitation. Suspension performance assessment.
Chapter 7: Stability
Lateral dynamics. Weave, wobble, and capsize. Simplified wobble analysis. Straight-running stability. Multi-degree of freedom model. Gyroscopic effects. Motorcycle stability versus speed. Sensitivity Analysis. Stability under acceleration and braking. Cornering stability.
Chapter 8: Handling
Rider behaviour. Feed forward and feedback strategies. Handlebar steering versus body leaning. Steady cornering. Linear analysis. Capsize. Non-linear effects. Rider posture. Cornering transient. Lane change. Frequency response functions. Effect of the speed. Steering torque decomposition.
Chapter 9: Case study: preliminary design of a sport touring motorcycle
Layout. Mass distribution. Powertrain. Requirements. Engine. Transmission. Acceleration performance. Fuel consumption. Suspensions. Requirements. Geometry. Load analysis. Stiffness. Damping. Summary. Comfort and roadholding assessment. Stability and Handling. Tyres. Front assembly. Stability. Handling. Sensitivity analysis. The road ahead.
About the Authors
Professor Roberto Lot, PhD is within the Department of Industrial Engineering at the University of Padova (Italy), previously he held the Chair in Automotive Engineering at the University of Southampton (UK). He has more than twenty years of experience in motorcycle engineering, focusing on vehicle dynamics and control of road and race vehicles. He has directed several national and international research projects and worked as technical and training consultant for several motorcycle manufacturers, contributing to make powered two wheelers safer, faster, and eco-friendlier.
James Sadauckas, PhD is a Staﬀ Engineer – Systems at Harley–Davidson Motor Company in the Vehicle Dynamics & Simulation Group. During twenty years in the motorcycle industry, he has been responsible for the ride & handling development of a wide variety of vehicles. His responsibilities include performing limit-handling testing, test method development, data analysis, multibody simulation, tyre modelling, peer mentoring, and interaction with technical collaborators. He is an avid motorcyclist and bicyclist and enjoys spending as much time as possible on at least one of two wheels.