During the Sepang tests, they hit the headlines. “They” are the Ducati, with a significant number of new features, some of which are very mysterious…
Still unable to fight on equal terms with the Japanese manufacturers, Ducati is pulling out all the stops to climb this last step which would allow it to seek the world title; a GP17 where everything, from the frame to the engine, is new, unlike Honda which still uses 2014 frames and Yamaha which is constantly refining its M1. But this is not enough, and the Italian engineers are working in all directions, whether aerodynamic, to compensate for the loss of the fins (let's wait to see the fairing on which they are working) or reduce drag (lenticular wheels), but also in more exotic areas, whether they result in a fork with carbon tubes, a “reaction exhaust” patent or this famous “black box” located under the saddle of all GP17s.
Everyone came up with their own hypothesis about it, from Petrucci's sandwich box to the control system of the future "jet exhaust"...
Matt Oxley, one of the three journalists most keen on MotoGP technique, puts forward another possibility quite affirmatively.
It is based on the observation that it is strange to add anything to a motorcycle so far from its center of gravity... unless it is a vibration damper. A hypothesis also based on a historical anecdote where Wayne Rainey's team managed by chance to move the chattering to a non-obstructive area by mounting a mass under the saddle (in this case the data recorder).
The idea is attractive: to attenuate the harmful vibrations of chattering with a mechanical system that is all the more effective as it is placed far from the center of gravity of the motorcycle.
The author then presents two possible damping systems.
The first, the Mass damper, is a mass damped by springs, a bit like certain anti-seismic systems for large buildings. This system was used on suspensions in F1 before being banned, the authorities not liking, in the event of an impact, to see masses of several kilos mounted on springs in the detachable nose of single-seaters.
Note, however, that in the case of the Ducati, to add mass to the rear, especially with a carbon fork at the front, without encouraging wheeling, you would really have to activate the “reaction” pot! All this seems to move away from the world of motorcycles and into science fiction, but why not: we cannot technically exclude this possibility.
The second system, favored by the author, is a “ inert", also called J-Damper, an invention of Professor Malcolm Smith of the University of Cambridge used by McLaren in F1, and to this day still legal.
Basically, it is the technological version of an object well known in the past, which then underwent an evolution, but whose principle remains the same: damping a vibration between two moving elements relative to each other. the other, by rotating a mobile mass.
Version A:
Version B:
The, we honestly admit that we don't understand how this could work on a motorcycle, at least at this location, since to be effective, the device must be connected to two moving points relative to each other, such as, for example, a frame and a swinging arm.
In summary, if we love to see Ducati looking in all directions for new technological solutions, we do not believe that the "Black Box" contains such a system ("inerter") but this however only reinforces the hypothesis of the Mass Damper, its mystery and its interest in our eyes…
We also recall that “active” suspensions, that is to say electronically controlled, are prohibited, and therefore probably an electronic chattering control system too, although it is not explicitly mentioned in the regulation.
