At Ducati, for the 2022 MotoGP season, there were a priori only two technical paths to follow: the well-known one of the GP21s assigned to Enea Bastianini, Fabio Di Giannantonio and Marco Bezzecchi. Then that of the GP22s supplied to the two official drivers, to the pair formed at Pramac and to Luca Marini. But from Qatar, this clear strategy became more complex: Pecco Bagnaia convinced that he needed an engine with characteristics more 2021 than 2022, leading Jack Miller into this decision. Jorge Martin and Johann Zarco have the 2022 engine. And the others are left with 2021. But that's not all: the front level corrector device, which provokes the ire of the five other manufacturers who have managed to do it to eliminate from the landscape for 2023, is also differently evaluated within the GP22 clan…
Indeed, during the official test at Sepang, Ducati revealed to its competitors that its technical teams had found a new way to push the limits of vehicle dynamics. Already in the past, the Borgo Panigale teams were the first to introduce spoilers, rear swingarm spoiler, Holeshot Device and Ride Height Device at the rear. The question for this new season was therefore what Gigi Dall'Igna and her team of engineers had imagined this time.
Last year, the Ride Height Device appeared on all machines, an attitude corrector which has the same role as the ailerons: it physically reduces wheelings, so that the anti-wheeling managed by the ECU does not does not need to take office. And that's where it comes in handy, because when it does, it decreases the torque available to the rear wheel, which hurts acceleration.
The answer to this also lies at the front of the GP22, not just at the rear. Ducati has installed a new Holeshot Device at the front of the Desmosedici, which appears to double as a front Ride Height Device. Where the old and simple Holeshot Device consisted of a simple latch and was only usable during the start phase, the new system is much more sophisticated and is used in the curve entry phases, but also when exiting the curve.
In this photo, taken during the Shakedown at Sepang, Johann Zarco has activated the front Ride Height Device, and the fork of his Ducati GP22 clearly remains in an at least partially compressed state after the front wheel breaks contact with the asphalt , the point of maximum acceleration.
However, this is not the case in this photo, taken in the same bend. However, because the front wheel no longer contributes to the anti-wheelie once it is off the ground, the front device has a smaller window of use than the rear.
Here, during a start simulation phase, the fork and shock absorber of Pecco Bagnaia's GP22 are also compressed.
Already, during the Shakedown at Sepang at the beginning of the year, Michele Pirro had published a video on Instagram where we observe a detail which differentiates the GP21 from the GP22: to activate the Ride Height Device at the front and rear, the in-house test rider only operates one mechanism, located on the upper triple clamp, whereas there are 2 mechanisms on the GP21: one for the front, and one for the rear. As soon as the Italian driver activates this mechanism, we immediately see the reaction on his prototype: the front and rear suspensions instantly lower and place his Desmosedici at ground level.
This photo was taken on the Ducati GP22 of Johann Zarco, the only Ducati rider to use the front Ride Height Device, and because he uses it he needs a different lever to activate the front Holeshot Device, for compared to other Ducati riders. Also, in this photo, we see that it has a small push lever (at the level of the Ducati Corse logo, located on the clutch fluid reservoir), then a lever to operate on the top of the triple clamp. If you move to the last image you will see the configuration of all other Ducati riders
Here, on one of the two Ducati GP21s from the Gresini team, we can clearly see the two levers that the other Ducati riders must activate their Holeshot Device devices, one for the front and the second for the rear.
So, by activating this device, the driver forces the front suspension to compress, which seems contrary to physics. As we know, riders usually activate the Ride Height Devide when they need to limit wheeling during acceleration phases. Thus, the ground clearance decreases and the center of gravity of the motorcycle evolves, so as to minimize wheelies.
But yet, during the acceleration phase, a simple physical phenomenon occurs: inertia, which is relatively easy to understand: in a car, when we accelerate, our bodies are glued to the seats. This inertia obviously occurs during acceleration on a motorcycle, and it naturally operates to “shift” the weight of the engine rearward.
Because of this phenomenon, forcing the fork to remain compressed during acceleration phases is much more difficult work than compressing the rear suspension, something naturally assisted by inertia.
Already difficult due to inertia, activating the front Ride Height Device has an increased level of technical difficulty because it requires acting on two suspension elements – the fork tubes – rather than just one at the rear.
But then why compress the fork rather than the shock absorber?
Lowering the front of the motorcycle has two advantages, in addition to being a very simple system to implement technically. First, it changes the balance of the motorcycle by putting more weight on the front wheel. In fact, the center of gravity moves forward by compressing the fork. Second, since the fork is not vertical, lowering the fork causes the front wheel to move slightly rearward, increasing the front static weight.
However, it is also simpler to place this system at the rear because there are more ways to compress the shock, instead of using hooks to hold the front down as seen previously. And it is more difficult for competitors to examine and copy this device.
How is the Ride Height Device activated?
The question is: how is this system activated and what is the technical activation mechanism? Firstly, an electronically managed system is prohibited by the regulations, so activation is manual and carried out by the pilot.
What generally confuses us is trying to explain how the action of a rider's thumb or index finger can compress the front suspension. This question is all the more relevant regarding the suspensions of competition motorcycles, which are very difficult to compress, whereas with this system it is done in less than a second. Certainly, MotoGP riders are athletes, but they still need the help of the laws of physics to carry out this compression, and for this we must address the subject of fluid pressure.
As an illustration, imagine a car jack which allows us to increase our efforts tenfold, of the order of 100 to 200 Newtons, by using a hydraulic system in order to be able to lift a car with a mass of approximately 1 ton , the equivalent of 10 Newtons, rounded off.
What does this have to do with the Ride Height Device? A hydraulic mechanism is placed behind the front fairing of the Ducati Desmosedici GP22 to facilitate the compression of the fork. The question that still remains open is how the connection between the activation device, located on the handlebars, and this hydraulic device is made. The first thing to see is that at the handlebar level, there is a steel cable coming out of the activation trigger.
On the Ducati, the Holeshot Device system is also controlled by a mechanical system, located at the front of the Ohlins suspension to compress the fork (see the photo above from the 2021 season). This rod is also connected to a steel sling. In 2022, Ducati still uses the same solution, but the carbon fork tube protection is more oval and covers more parts of this Holeshot Device, while improving aerodynamics in this section.
Thus, at the driver's control level there is a steel cable, connected to the hydraulic device, which transfers and amplifies the pressure exerted by the hand in the suspension travel. No need for riders to brake hard just before the start to compress the suspension, as we see in Motocross. At the exit of this device, another steel cable connects to the Holeshot Device itself. What differentiates Johann Zarco's GP22 from the other Ducati is that the French rider uses the Ride Height Device before the race, something that his teammates from the Bologna brand have tried, but not adopted, while the GP22s have it. .
But is it only Ducati that developed this system? Last season, Aprilia also seemed to have developed a similar device, and some even suspected that it could be automatic which, when the rider activates the Ride Height Device mode, then activates a mechanical system which allows the front and rear Ride Height Device to be connected.
What does the regulation say?
In the MotoGP regulations, an extract of which is available above, it is stipulated that: “Electrically/electronically controlled suspension, ground clearance and steering damper systems are not permitted. Adjustments to suspension and steering damper systems can only be made by manual human interventions and mechanical/hydraulic adjustment devices.
The use of any device that changes or adjusts the ride height of the motorcycle while it is in motion is prohibited, with the sole exception of mechanical/hydraulic passive suspension spring preload adjustment devices, e.g. front fork cap, mechanical dials for manual preload adjustment, remote shock spring mechanical/hydraulic preload adjusters operated by a manual button. »
Obviously, this amplification device, which can be used as a trigger for the mechanical system of the Ride Height Adjuster, has been in the heads of the technical teams for a long time, with the idea of ensuring that riders do not need to determine where in the circuit they must activate, or not, this system.
Photos: Dorna Sports
