The main goal is to design a very light and rigid structure. To reach the lowest mass, it was decided to develop a tubular welded truss structure (completely different from the cast Gp10 swingarm, taken from a Cagiva Mito). Such structure is very easy to be manufactured and, at the same time, guarantees good mechanical properties in terms of torsional and flexural stiffness. The handling of the motorbike is strongly influenced by the geometry of the main points of the swing arm: pivot, hub, sprocket. Such points are aligned in order to have the maximum control over the power transmitted to the rear wheel through the chain. Because of the deformation of the swing arm (under stress), these points may not be perfectly under design condition and thus, the dynamic behavior significantly changes. Therefore, strong limitations on the deformation have to be respected.
 

Geometrical constraints. Since the swing arm has to be assembled with all the other components, before any design some characteristic points had been fixed. Thanks to these standards, common to all the groups, it was possible to independently develop the single components and then assemble them.

Size constraints. It was necessary to consider the volume occupied by other components: wheel, transmission chain, shock absorber, pro-link connection and exhaust pipe. Also the motion of some of these parts (shock absorber, chain, pro-link) was considered. Sizes and positions of these parts were fixed and given and were designed according to their specifications.

In order to face different racetracks, the swing arm is composed by an interchangeable tip (cast aluminum plate) and a fixed steel body. Changing the final part, in fact, the handling can be tuned.

Furthermore, it  was decided to design a double-arm swingarm because of its evident advantages, dynamically and in terms of stresses, due to its symmetry. 
 

Another constraint is the manufacturability of the component. Since the swing arm will be handmade, it should have an easy shape, based on bended and welded tubes (with constant circular cross-section).

In the  development of the design of the swingarm some modifications were performed in order to match continuously with the groups that are producing other components through a feedback among us.

Other "non-technical" constraint  were the deadlines of the several phases of this project.