Because in the SKE there is no full rotation

The SKE differs from conventional equipment in its innovative pedal movement. In fact, the SKE does not involve a full rotation of the pedals, but rather an alternating movement on a circumference with a much larger radius than in a normal bicycle. This design choice is the basis of the SKE's effectiveness for safe strength training.

Theoretical circumference of pedaling on the SKE

Incomplete rotation for effective thrust

Full rotation was deliberately eliminated to allow each push to be made starting from a standstill. Therefore, it is not possible to use the kinetic energy accumulated during the movement to reduce the intensity of the next rotation.
On a traditional bike, once you start pedaling and accumulating speed, inertia helps you maintain the movement: you don't need to apply a great deal of force to each pedal stroke, because the moving wheels keep turning thanks to the accumulated energy. On the SKE, on the other hand, each thrust starts from a standstill and there is no full rotation: it means that each and every movement requires a maximum thrust that is independent of the previous energy.
In practice, you cannot use the inertia of pedaling to "lighten" the work in subsequent thrusts. This approach, in addition to maximizing neuromuscular activation, ensures that muscles are constantly working to generate force, making training more intense and focused than cycling.

The arc described by the SKE

Although the radius of the circumference described by the pedal is very large, the arc described by pushing on the SKE has a length equal to that of a normal pedal stroke, where, however, the ability to push is greatly reduced near the upper and lower dead spots.

Intense pushing ability throughout the movement on the SKE

This design feature enables continuous, intense and effective thrust throughout the movement, making the most of every phase of the thrust without reduction in applied force.

The gesture appears natural and is carried out respecting not only the body position typical of using a bicycle, but especially the angles and trajectories assumed by the joints of the foot, knee, hip and torso. 

Neuromuscular coordination

Thrust after thrust, workout after workout, the neuromuscular system learns to coordinate the gesture and apply force along a wider angular arc than in full pedaling. This leads to a significant improvement in power and performance, making the SKE especially useful for even the most demanding, high-performance athletes. Indeed, the ability to apply additional force over a wider angular sector will result in increased power during both short and long intervals.

Maximum force on the SKE and Force on the bike

Conclusion

In summary, the elimination of full rotation in the SKE pedals is a design choice aimed at maximizing training effectiveness. Each push starts from a standstill, requiring maximum muscle effort and allowing for significant improvement in strength and power.