The second generation "Electronic Suspension Adjustment", or ESA II, allows the suspension to be adjusted very comfortably and adapted to the riding mode and load.
The selectable characteristic curves for suspension and damping enable a previously unknown degree of adjustment of the chassis to road conditions and load with the greatest possible operating comfort.
This system, which is unique within the motorcycle market, allows the driver to adjust both the rebound-stage damping of the front and rear spring struts and the spring mount ("spring preload") of the rear spring strut, but also its spring rates and therefore the hardness of the spring by electronic means. This is achieved in a convenient way by means of the multi-controller in conjunction with the menu guidance on the TFT colour display.
To keep operations as simple as possible and to prevent mistakes when setting the suspension, to begin with the rider only enters the loading status ("solo", "solo with luggage" or "with passenger and luggage"). The adjustment of the relevant spring mount or spring rate is then automatic, with the system coordinating both of these values.
In addition, the rider selects the "Comfort", "Normal" or "Sport" damper setting and therefore the required suspension character of the machine. Working with these specification, the electronic controller uses the optimum parameters to calculate the appropriate damping rates and uses an electric motor to set these on the spring mount. In total, there are nine different variants available. The damping rate is changed by means of small stepper motors on the dampers.
The additional adjustment of the spring rate allows the level of the motorcycle to be perfectly adjusted to different loading states and thus ensures an even higher degree of stability, manoeuvrability and comfort. Even under maximum loading conditions, with passenger and luggage, full cornering clearance is maintained, enabling a sporty riding mode. In addition, the adjustment of the spring rate significantly reduces the danger of drifting under extreme loads.
It is possible to change the damper setting ("Comfort", "Normal" or "Sport" ) at the press of a button, even while moving. For functional and safety reasons, the spring mount can only be changed when stationary. An electric motor with transmission is used to vary the spring rate.
The change in spring rate is facilitated by two springs switches in series. An elastomer element (Cellasto) in combination with a conventional helical spring below absorbs the forces during compression. The radial outward expansion of the Cellasto element is permanently limited by a steel sleeve. On the inside, an electrohydraulic mechanism is used to move an aluminium sleeve. The position of the inner sleeve influences the inward expansion of the Cellasto element and therefore its spring rate. This has the same effect as the use of two springs of different strength. If the inner sleeve sits on the steel spring, the Cellasto element will not function and only the steel spring will work. If the internal sleeve is then moved, it is also possible to vary the spring mount of the steel spring, in other words the "spring preload".
The enables the static normal position and the rising geometry to be maintained to optimum effect in all loading states. The additional adjustment of the spring rate over the broad range from 110 to 160 N/mm made it possible to spread the "Comfort", "Normal" and "Sport" settings broadly for ESA II, thereby clearly influencing the riding mode.
The advantage of electronic suspension setting with ESA over a conventional mechanical setting is the fact that all suspension components are immediately coordinated, so that "normal users" can avoid errors. This will enable riders to avoid the need for awkward and time-consuming manipulation of tools, instead of which they can make the adjustment conveniently within seconds at the press of a button. This makes it possible to adjust the suspension even at short notice, for example when spontaneously carrying a passenger or when the characteristics of the terrain suddenly change.