The Relationship between Twist Axis and Effective Torsional Stiffness of a Motorcycle Frame

  • M. Raines
  • G. E. Roe
  • T. E. Thorpe


The design of a motorcycle frame has an important influence upon the machines weave and flutter oscillation characteristics. This paper deals particularly with the torsional stiffness of the frame and it underlines the importance of the position of the twist axis, i.e. the axis about which the frame twists. It is demonstrated that because the twist axis moves, the torsional stiffness of a frame may reduce as individual members are stiffened. The position of the twist axis of a motorcycle frame is determined by finite element techniques, and this is then related to its stability and handling characteristics.


Lateral Force Torsional Stiffness Rear Wheel Finite Element Technique Speed Flutter 
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  1. 1.
    Roe, G.E.; Thorpe, T.E. ‘Improvements to the stability, handling and braking of high-performance motorcycles.’ Proc. Int. Motorcycle Safety Conf. Washington, USA, May 18–23, 1980. Vol.11Google Scholar
  2. 2.
    Sharp, R.S.; Alstead, C.J. ‘The influence of Frame Flexibility on the Lateral Stability of Motorcycles.’ J. Mech. Eng. Sci. 16. 2 (1974)CrossRefGoogle Scholar
  3. 3.
    Kane, T.R. ‘The Effect of Frame Flexibility on High Speed Weave of Motorcycles.’ S.A.E. Paper 780306, 1978Google Scholar
  4. 4.
    Hasegawa, A.; Pacejka, H.B. ‘Analysis of controllability and Stability of Motorcycles: Analysis of Stability at High Speed Driving.’ Proc. Int. Mototcycle Safety Conf. Washington. U.S.A. May 18–23, 1980 Vol.11.Google Scholar
  5. 5.
    Roe, G.E.; Thorpe, T.E. ‘A solution to the low speed flutter instability of motorcycles’ J. Mech. Eng. Sci. 18. 2 (1976)CrossRefGoogle Scholar
  6. 6.
    Roe., G.E. ‘Theory of castor oscillations’ J. Mech. Eng. Sci. 15. 5 1973Google Scholar
  7. 7.
    Timoshenko, S.P. ‘Theory of bending, torsion and buckling of thin-walled members of open cross section.’ J. Franklin Inst.239 Nos.3,4,5.(1945)Google Scholar
  8. 8.
    Wilson, E.L. ‘SOLID SAP-A static analysis program for three dimensional solid structures’ SESM Report 71–19, Dept.of Civil Eng. University of California, Berkeley, 1971Google Scholar

Copyright information

© Springer Japan 1986

Authors and Affiliations

  • M. Raines
    • 1
  • G. E. Roe
    • 2
  • T. E. Thorpe
    • 2
  1. 1.Department of Mechanical EngineeringSunderland PolytechnicSunderlandUK
  2. 2.Simon Engineering LaboratoriesUniversity of ManchesterUK

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