INDEX

INTRODUCTION: description of the general aspects of a motorcycle instabilities in the track (Weave, Wobble, Capsize, Pitch, Roll, Torsions, Displacements etc...) and how a good suspension system can limit these phenomenons; historical evolution of the types of motorcycles rear suspensions; ALL THE PHENOMENONS SDESCRIBED IN THIS ARTICLE HAVE BEEN STUDIED THROUGH THE SOFTWARE SUSPENSION 4.0 BY SOFT-ENGINE;

THE CONCEPT OF PROGRESSIVENESS: concept of progressive-rate of compression, the suspension linear, progressive and digressive behaviour;

MAIN KINEMATICS QUANTITIES: the principal kinematics quantities, important to define the behavior of the suspension, like:

LEVERAGE RATIO: this quantity is very used in the Anglo-Saxon countries; it mathematically expresses the behavior of the suspension respect the wheel travel;

RATIO SHOCK ABSORBER COMPRESSING/WHEEL TRAVEL OR MOTION RATIO;

DEFORMATION PROGRESSIVENESS;

SPEED DEFORMATION PROGRESSIVENESS;

STATIC QUANTITIES: the principal static quantities, important to define the behavior of the suspension, like:

FORCE AT SPRING AND FORCE AT SHOCK;

FORCE AT WHEEL; 

WHEEL RATE: very important quantity, tied up tightly to the leverage ratio

LAST GENERATION KINEMATIC MECHANISM ANALYSIS: A study of the most recent suspension layouts, using software SUSPENSION 4.0: Yamaha R1 2004, Kawasaki ZX6RR 2004, Kawasaki ZX10RR 2004, Triumph T600 2004, MV Agusta F4 1000 2005, Ducati 749 2004, Honda CBR 600 2005

THE REVERSE FUNCTION: how "reverse function" works: by an opportune software procedure, it is possible to modify an existing layout (or to create a new one) beginning from a known law of movement. This is a reverse engineering problem; 

A GUIDED EXAMPLE:implementation of the Reverse Function procedure into SUSPENSION 4.0 software, the show of the automatic procedures software to modify a Kawasaki ZX10RR layout so that its leverage ratio becomes equal to the Kawasaki ZX6RR layout one, taken as reference suspension.

DUCATI 749 - KAWASAKI ZX6RR: how it has been possible to modify a Ducati 749 layout so that its leverage ratio becomes equal to the Kawasaki ZX6RR layout one. It is possible to show that all the last generation of kinematic mechanisms (above listed), can be modified in a way that their leverage ratioes are coicident, even if, before the modify with the reverse function, their leverage ratioes were very different. Send an e-mail to: info@soft-engine.com if you wish more information about this.

CONCLUSIONS.

This paper concerns the study of motorbikes rear variable-stiffness suspension system using a pourpoused software. The rear suspension system is composed by a shock-absorber located between two elements of a quadrangle; this kind of linkage is drawn in a way that the spring compression law is suitable to vehicle ride contol. In this document is shown how, applying the Reverse Function method, is possible to find the same leverage ratio from suspension layouts also totally different. In this article there are several application examples of  many recent motorcycles layouts with the discussion of results.