VIBRATIONAL MODES OF MOTORCYCLES IN CURVES

Experimental observations have indicated that the damping of lateral oscillation may decrease when a motorcycle negotiates a curve, possibly the result of an interaction between the in-plane and out-of-plane vehicle motions. This phenomenon is investigated using an eight degree-of-freedom mathematical model of a single-track vehicle. The model allows for the following motion components: lateral, yaw, roll, and steer (out-of-plane), and bounce, pitch, and front and rear wheel hop (in-plane). The model analyzes the strong coupling between the two vibrational modes when a motorcycle corners at large roll angles. The tire is modeled to describe steady-state and transient responses. Eigenvalues of two vehicle configurations have been calculated via a computer program. The expected coupling of vibrational modes has been clearly demonstrated, the most significant phenomena being a destabilization of the wobble mode and possibly the original weave mode and a decrease of the wobble frequency. Future research includes the extension of the model to complete rider behavior (active as well as passive) and refinement of tire behavior to include the irregular road surface. Road and laboratory studies will be conducted to verify and, if necessary, adjust the model.

  • Supplemental Notes:
    • Conference held in Washington, D.C., 18-23 May 1980. Also published in HS-029 680, International Motorcycle Safety Conference Proceedings. Volume 2, p 501-43.
  • Corporate Authors:

    Motorcycle Safety Foundation

    780 Elkridge Landing Road
    Linthicum, MD  United States  21090
  • Authors:
    • KOENEN, K
    • Pacejka, H B
  • Publication Date: 1980

Media Info

  • Features: References;
  • Pagination: 43 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00389650
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: HS-029 684
  • Files: HSL, USDOT
  • Created Date: Oct 30 1984 12:00AM