Almost lost in BMW's celebration of Chaz Davies winning both World Superbike races at Motorland Aragon in Spain was Sylvain Barrier's victory aboard a BMW in the FIM Superstock 1000 Cup race at the same event. Barrier's win itself was not unexpected - the Frenchman is the reigning champion in the class - but the race marked a milestone in that Barrier rode a BMW HP4 equipped with DDC (Dynamic Damping Control), BMW's semi-active electronic suspension system.
According to Andrea Buzzoni, General Manager of the BMW Motorrad WSBK effort, "Thanks to the development work that the team have done over the last three months, BMW wrote an important page in the history of motorcycle racing as it is the first bike to win with an innovative electronic damping system."
Dynamic Damping Control as used on the production HP4 incorporates electronically actuated valves inside the fork and shock to vary damping almost instantaneously. The system looks at data from the ECU as well as lean angle and rear shock travel, analyses those parameters and determines optimum values for compression and rebound damping. For example, under acceleration the system can stiffen the shock's damping to reduce squat; damping can also be changed as the motorcycle leans into a corner, and even depending on the rate of roll.
The rules for the Superstock 1000 class allow fork internals and the rear shock to be replaced on bikes with conventional suspension. However, for electronically controlled suspension, all the mechanical and electrical components must remain stock. This is a significant penalty for the use of DDC; aftermarket fork cartridge kits and shock absorbers are built with performance in mind and with little regard to cost, whereas the DDC components were designed with mass production - albeit limited - in mind. For the production-based BMW setup to be competitive in its first event is an impressive accomplishment.
Key to Barrier's and BMW's success with DDC at Aragon was no doubt the company's HP Race Calibration Kit for the HP4, which unlocks some interesting features of the system for racetrack use. In stock form, basic stiffer/softer changes can be made to the front and rear damping, and front compression and rebound are tied together; only on the shock can compression and rebound be separately adjusted. Adding a front travel sensor (a rear travel sensor is stock, the front sensor is part of the HP kit) allows for independent fork changes. And with the HP Race lap timer also installed, DDC settings can be altered on a corner-by-corner basis; the system tracks distance from the start/finish beacon and makes changes accordingly. This alone is a significant advantage over any conventional system that cannot be similarly adjusted once underway.
It's interesting to note that the rider plays an influential role in the development of any electronics system. Buzzoni said after the race at Aragon, "I want to congratulate both the team along with our colleagues in Munich for developing the system and Sylvain, who knows how to make perfect use of this new technology."
With Dynamic Damping Control now proven successful on the track in the Superstock class, it may not be long before we see the system's use in World Superbike also.
{fcomment}