Motorcycle Front Wheel Patter in Heavy Braking

Practical stability analysis for transient system dynamics

“…Inplane instability phenomena, such as wheel patter [35], are left out of consideration, because these can be assessed independently. Figure 4 shows stability results for the case in which only rear wheel braking is applied.…”

“…Only deviations in the yaw angle, roll angle, and steering angle and their corresponding angular velocities, ω z , ω x , andβ, are considered to be important. Inplane instability phenomena, such as wheel patter [35], are left out of consideration, because these can be assessed independently. Figure 4 shows stability results for the case in which only rear wheel braking is applied.…”

Bicycles, motorcycles, and models

“…An interaction between the front wheel-hop and wobble modes occurs when the two modes are close enough in terms of natural frequency. This interaction is possibly linked to wheel patter, which is known anecdotally [78]. The coupling of the inplane and out-of-plane motions also suggests the possibility of road excitation signals being transmitted into the lateral motions of the vehicle, causing steering oscillations [43].…”

Patter instability of racing motorcycles in straight braking manoeuvre

“…As revealed by data analysis on instrumented motorcycles, this extreme circumstance is preceded by vibrations in a frequency range between 7 and 10 Hz, involving fluctuations of both spin velocity of the front wheel and pitch of the vehicle, which cause oscillations of the front downforce at the same frequency. This phenomenon, referred to as front wheel patter, was first studied by Sharp and Giles [1] on the basis of previous work on automobile axle tramping vibrations [2], leading to the definition of a four degrees of freedom minimal model. In [1] only the the front assembly was considered, pivotting about a horizontal axis and spring restrained to an infinitely massive rear frame, with additional allowed motions consisting of plunging of telescopic forks, spinning of the wheel and spinning of the tyre tread band, restrained by the tyre carcass elesticity.…”

“…This phenomenon, referred to as front wheel patter, was first studied by Sharp and Giles [1] on the basis of previous work on automobile axle tramping vibrations [2], leading to the definition of a four degrees of freedom minimal model. In [1] only the the front assembly was considered, pivotting about a horizontal axis and spring restrained to an infinitely massive rear frame, with additional allowed motions consisting of plunging of telescopic forks, spinning of the wheel and spinning of the tyre tread band, restrained by the tyre carcass elesticity. Stability was investigated by imposing constant travelling speed to the rear frame, then integrating numerically the non-linear constant-coefficient equations of motion in the time domain.…”