Design of a Moto3 Racing Motorcycle MSc Dissertation

David Ojea Cerradelo September 2011

Moto 3 is the four stroke replacement for the 125cc class, which has been a mainstay of the World Motorcycle Championship since it's inception in 1949. This switch reflects the lack of interest in two stroke technology in today's motorcycle market.

•  Prototype Chassis •  Carbon fiber fairings •  Single cylinder 250cc 4 strokes

Features •  148kg minimum (including driver) •  Circa 50hp •  0-100 kph in 5sec

Introduction

-  Complete a technical research

-  Solid modelling of the complete motorcycle chassis components

-  Structural analysis of main frame and swingarm

-  Design front and rear suspension

NOT INCLUDED

-  Design motorcycle fairing

-  Assess performance of the motorcycle

-  Business case

Objectives

Design a racing motorcycle that meets the FIM technical regulations to perform in the Moto3 World Championship.

Geometrical Concerns

-  Similar handling to 125 GP bikes

-  Adjustable Design (wheelbase, castor angle and trail)

-  Chain Angle, Squat , CofG position and Ergonomics

Wheelbase, castor angle and trail define the geometry of a motorcycle

Components Design

Prototype components

-  Main Frame (Reynolds Steel 631) and Swingarm (Al 7079). Stiffness

to Weight optimization

Proprietary components

-  Front Fork, Rear Shock, Engine, Wheels…

Suspension Design

Front Suspension

-  Castor optimization

Rear Suspension

-  Rising wheel rate

-  Linkage Hardpoints

Results •  Main frame and swingarm heavier than 125 GP designs •  Chassis stiffness meets suggested racing motorcycle targets •  The wheel rate avoids bottoming out of the suspension Future Work •  Incorporation of Flexible bodies and FTire model •  Simulate rider behaviour and chain reaction for dynamic study •  Design motorcycle fairing •  Evaluate performance in a lap time simulator

Conclusion A motorcycle capable to perform in the Moto3 championship was designed. This design incorporates tools to get the best possible setup for every track and rider by mean of adjusts in wheelbase, caster angle and trail.

Results and Conclusions

Questions & Answers

Thanks for your attention