Unique to the worldwide motorcycle market, this system provides riders with electronic controls that not only facilitate adjustments to the rebound-stage damping of the front and rear spring struts and the spring base of the rear spring strut ("spring preload"), but also to its spring rate and "tightness". This is all conveniently handled with one multi-controller, together with the menu navigation on the TFT colour display.
In order to best simplify control and avoid unintentional setting errors, riders are merely asked to enter the load status ("solo", "solo with luggage", or "with pillion passenger and luggage"). The system then analyzes the corresponding spring base or spring rate and configures them automatically.
According to their personal riding preferences, riders can also select between chassis and suspension adjustments "Comfort", "Normal", or "Sport", which affect how the machine responds to their control. The electronic control unit then analyzes these specifications and calculates the appropriate damping rates using optimal parameters. It then actuates an electric motor that configures the spring base accordingly. A total of nine different setting options are available. The damping rate is modified at the dampers by means of small stepper motors.
These additional modifications to the spring rate mean that the vehicle level can be optimized to various loads for an even higher level of riding stability, handling, and comfort. Full banking freedom is retained even under maximum load with pillion passenger and luggage for an enhanced sporty ride. These adjustments to the spring rate also greatly reduce the risk of bottoming out under extreme loads.
The shock absorber settings ("Normal", "Sport", "Comfort") can be changed at the touch of a button, even while the vehicle is moving. For functional and safety reasons, the spring base may only be changed when the vehicle is stationary. An electric motor with gears is used to modify the spring rate.
The spring rate is changed using two springs connected in series. Here, the compression forces are absorbed by an elastomer element (Cellasto) combined with a conventional coil spring installed below. The outward radial expansion of the Cellasto element is permanently contained inside a steel sleeve. On the inside, an aluminum sleeve is moved through electrohydraulically. The position of this inner sleeve affects the inward expansion behavior of the Cellasto element, and therefore its spring rate. This has the same effect as two springs with different degrees of tightness. If the inner sleeve rests against the steel spring, the Cellasto element loses its function and only the steel spring is affected. If the inner sleeve is moved further along, the steel spring base or "spring preload" can also be modified.
This allows the normal static position and riding geometry to remain optimized in all loads. Additional adjustments to the spring rate across the wide range of 81-118 lbs-ft. serves to augment the "Sport", "Normal", and "Comfort" settings in ESA II, significantly enhancing rideability.
As compared to conventional mechanical adjustment techniques for spring preload and damping characteristics, the advantage of using ESA electronic chassis and suspension adjustment lies in its constant and immediate harmonization of all of the chassis components and in its prevention of "normal user" error. Riders are also spared the time-consuming inconvenience of tool adjustments, helping them make modifications in mere seconds at the simple touch of a button. This makes taking on pillion passengers at a moment's notice or handling unexpected road surface changes a breeze.