BMW is Developing Active Suspension for Motorcycles | First Look

Dynamic Damping

In our recent “Class of 2011” sportbike comparison, we openly wished BMW’s S1000RR offered pushbutton electronic suspension adjustment. The German manufacturer already offers ESA on many of its large touring bikes; could it be that difficult to add a sport-specific version to what is already the most electronically advanced motorcycle on the market? Someone in Berlin must have been thinking the same thing, because BMW has released preliminary information regarding the Dynamic Damping Control (DDC) system it is currently developing. Unlike ESA, which only changes static suspension settings, the advanced DDC system will allow spring and damping rates to automatically change in real time, in direct response to vehicle-dynamic feedback.

Active suspension is already a reality in the automotive world, but suspension set-up for motorcycles remains an art of compromise. Suspension that is firm enough for high-speed, aggressive sport riding is invariably too harsh to deliver a comfortable ride on a bumpy city street. DDC would eliminate this compromise, instantly and automatically altering suspension action in response to how and where the rider is travelling at any given moment. The result is the perfect ride for any conditions, whether hustling down a twisty road or cruising along a potholed interstate.

BMW hasn’t announced a release date for DDC, beyond saying it will appear on motorcycles “in the near future.” It also hasn’t indicated what models the system will debut on, though the flagship K1600GT tourer seems the obvious candidate—followed, hopefully, by the pure-sports S1000RR.

How DDC Works

BMW’s Dynamic Damping Control gathers input from a number of systems including the ECU, wheel-speed sensors, tilt/roll sensors and spring travel sensors located on the fork and shock. This data creates a comprehensive picture of how the motorcycle is interacting with the road surface at any given moment, then alters compression and rebound damping accordingly. A variable-ring aperture alters the shock-valve openings to increase or decrease fluid passage, effectively changing the damping characteristics. BMW has said nothing about the software running the system, so it’s unclear how many times per second the system will sample data. Or whether the front and rear suspension “communicate” with each other so the rear suspension, for example, can anticipate obstacles that the front has already encountered. These capabilities are presumably being refined now.

DDC versus ESA

The latest version of BMW’s ESA II electronically adjustable suspension mechanism instantly alters both spring preload and compression/rebound damping at the touch of a button. The rider chooses between three spring preload settings (rider, rider with luggage and rider with passenger) and three ride modes (normal, comfort or sport). The bike must be stopped to change the preload settings, but ride mode settings can be changed on the fly. The biggest difference between ESA and DDC is that the latter is dynamic. DDC automatically and constantly changes in response to road conditions in real time, with almost infinitely variable settings. ESA is limited to the three predetermined settings, each of which must be selected manually.