MotoGP technique: Ducati’s “Salad Box” dissected

The theories about Salad Box have ranged from the most simplistic, such as a storage location for electronics, to the most exotic, imagining a KERS system similar to that used in F1. The rumor of a variable geometry exhaust, which would disrupt the aerodynamics at the rear of the bike and thus prevent opponents from taking the suction, died hard, but the box is much larger than what would be necessary to accomplish this single task…

This black box has caused a lot of ink to flow. She was named Salad Box by Ducati test rider Michele Pirro, whose response to journalists asking what it was for, was given with a touch of humor “to carry a sandwich in it”. But this one having required the entire rear exhaust system to be offset, it was clear that this was not just a simple addition, but a key part of the bike’s design.

The motorcycles of Jack Miller and Danilo Petrucci let us see the famous black boxes

We were able to observe the inside of it in 2018, on the occasion of the double fall of Jack Miller and Danilo Petrucci, and realize that inside this box was hiding… another box, connected to electronics, inside which the real secrets remain hidden!

It could in fact integrate a Mass Damper with repercussions on the handling of Italian machines, although Ducati has never revealed anything about it. The first tests on this subject date back to 2014, when Ducati had integrated 2 cylindrical masses at the rear of the fairing. At that time, no Ducati competitor had copied the system (although Honda tested a similar system last year). We could draw a parallel with the J-Dampers, used in Formula 1.

We can see 2 masses on either side of the exhaust

Let’s talk a bit about physics, applying it to mechanics, with the moment of inertia:

I = M x R²

With I, the moment of inertia – M, the mass – R, the distance from the fulcrum

We quickly realize that if the mass increases, the moment of inertia also increases. Moreover, if this mass is placed far from the position of the fulcrum, or from the center of gravity of the motorcycle (to put it simply, located at the level of the engine), there will be a strong impact on the inertia. However, this moment of inertia is the physical translation of what a pilot calls chattering (we broached the subject in 2017, concerning this famous Black Box on the Ducati).

The former MotoGP rider, Colin Edwardssaid about chattering that the sensation is “like sitting on a jackhammer”. As for Cal Crutchlowhe compares this to encountering a Bulldozer which passed just before him on the bend… We understand why the teams are working to reduce its impact!

In the past, wayne rainey had already unwittingly benefited from the benefits of this kind of system when the data recording box, which weighed 2kg, had been placed under his saddle. This had shifted the bike’s center of gravity slightly and lessened its chattering concerns.

The Salad Box is an easily identifiable technical element on Ducati

But back to the Salad Box of the Ducati. While a conventional Mass Damper would likely be used to help absorb shock, vibration and chattering, a rotating Mass Damper could also resist the normal gyroscopic forces found on a motorcycle and – for example – make it easier to right the motorcycle. at the exit of the curve.

Most track watchers agree that the handling of the Ducati has improved since the appearance of this Salad Box. Another advantage of a rotating system to counteract such forces is that less mass would be required compared to a conventional system that moves weight back and forth.

The video above shows how a small spinning gyroscope, similar in size to the Salad Boxcan help dampen vibrations.

The energy recovered by this Mass Damper, which reduces chattering, can also be stored or even released. But this secret has not yet been revealed! It is the famous KERS of F1 which could be adapted in MotoGP…

What is clear is that Ducati has never officially revealed what was hidden in this box…

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