MOTOGP & WSBK TECHNICAL

DIFF CHASIS BETTWEN MANUFACTURER

Chasis/Main frame merupakan antara faktor paling penting bg memastikan sesebuah motorsikal itu mudah dkendalikan.Yamaha,Honda & Suzuki menggunakan "traditional Chasis" (Mainframe utama) bagi jentera mereka sdang Ducati dsmping cuba mngubah tradisi mereka juga berekperimentasi dengan teknologi (cehhh...ayat aku!!!)

YAMAHA





Yamaha masih menggunakan "traditional chasis" dimana "main frame" motorsikal mereka digabungkan sekali pada chasis.Yamaha terkenal dengan chasis DELTABOX mereka.Chasis Motogp yamaha adalah chasis terbaik didalam grid Motogp hasil pembangunan yamaha bersama Valentino "Raja" Rossi

HONDA





Pasukan Honda sebelum ini bnyak mnghadapi masalah dengan chasis mereka.Pnyelesaian diambil dengan menukar fork dan saspensi dari showa kepada ohlins dmana fork dan saspensi ohlins nmpaknya lebih "mesra" dengan tayar bridgestone.

DUCATI









Ducati mengubah tradisi dengan menjadikan Enjin mereka sebagai chasis/mainframe utama.Tidak dapat dipastikan kenapa jurutera2 ducati ini begitu berani mempertaruhkan imej ducati dengan melakukan sesuatu yg lari dari kebiasaan.Dengan pengunaan aluminium sebagai chasis utama,kadar lentur (flex) casis mudah ditentukan tetapi tidak dengan pengunaan CF.Setakat hari ini,eksperimentasi ducati masih menemui jalan buntu nmun mereka ttap menggunakan cara mereka.Mungkinkah suatu hari nnti cara duacti ini akan berjaya?

Under the Hood: MotoGP electronics is where the rubber meets the road

It's fast machines all over again. A previous interview with EFI engineer Danilo Casonato of Kawasaki's MotoGP Engineering Team touched on how electronics get woven into that team's entries for the top tier of motorcycle racing. At this year's MotoGP race at Mazda Laguna Seca Raceway, in Monterey, Calif., I went back for more, primed by my earlier introduction to a high-technology, one-off race-hardware world characterized by big-time speed, sound and an underlying air of secrecy.

To better grasp the whole of MotoGP electronics, a repeat visit in Kawasaki's pit-lane paddock was accompanied by a session each with Yamaha's GP-team data engineer, Suzuki's GP crew chief along with a co-founder of Germany's 2D Systems, a key sensor and electronics box supplier to those three factory teams.

The almost absurd power-to-weight ratio of MotoGP bikes has led teams to pursue sophisticated machine-control intervention to help keep riders on two wheels, and one of my primary questions revolved around autonomy in bike control during the race. Since the pit is prohibited from making in-race changes, race-time modifications--such as ignition timing and throttle-fuel mapping--must be made by the rider and onboard systems that determine if, when, how and even where performance adjustments are implemented.



But less clear is how these decisions are driven by real-time sensory inputs. Does the bike position on-track enter into the control equation and, if so, how is it done reliably? How is the rider's throttle application modulated with electronic "ride-by-wire" on the way to air/fuel delivery? Drilling deeper gets one to the question of sensor arrays used to drive all the control functions. What's being measured, what data do these sensors provide, and how do teams use and collect data? Figuring prominently are datalogging, data analysis, and decision-making based on both. In an ocean of data, how do you swim in the right direction to improve performance?
I put forth lots of questions and, in the end, got quite a few answers, thanks to the time each team graciously extended to highlight the electronics engineering behind its individual efforts.


Getting revved up

Kawasaki's Ian Wheeler arranged a discussion with Andrea Dosoli, EFI technician onsite at Laguna Seca this year. As a former crew chief and current motocross rider, Andrea's focus on electronics systems is balanced with the perspective of the entire system and the rider responsible for making it all work on the track.

This year, Kawasaki's main focus is a new, more capable engine control unit (ECU). Working more closely with long-time partner Magneti Marelli of Italy, Kawasaki sees a deeper development role as strategic imperative for a competitive control system. Similarly, post-action data analysis is placing greater demands on a rich data set and software analysis to bring home a clearer picture of the bike in action.


Kawasaki's electronics control system

But mechatronics and control loops can still fall short when it comes to a human-driven activity. Despite moves by other teams to a full ride-by-wire system (where throttle application is electronically translated into acceleration of the engine) Kawasaki maintains--at least for now-- their "half-and-half" system. A physical cable from the rider throttle input controls half of the four-cylinder throttle bodies but electronic systems pick up the rest. In essence, Dosoli acknowledged a team "philosophy of feel," which keeps the rider more fully connected to the machine.

To my surprise, Dosoli indicated that real-time control based on the location of the motorcycle on the circuit had not yet fully made the transition from test track to racetrack. The system is definitely in the later stages of development and its full-time use on the race bike is fairly imminent, though Dosoli refused to be drawn on whether elements of the real-time control system are in use on the team's current MotoGP machines. What Dosoli would confirm is that GPS is the way forward for reliable position-pinning on track, as inertial navigation systems remains plagued by noise and signal ambiguities.

To be sure, data collection for later analysis relies on GPS location-stamping, but heat-of-the-moment decisions are made by learning which sensors tell the story with enough accuracy to manage the motorcycle's response to rider inputs and bike behaviors.



Putting the power down

A two-year-old mandate reducing MotoGP engine displacement has given engineers a bit less raw power to manage. Smooth power delivery is key; the measures the ECU takes to level the peaks and valleys of engine output become more tractable when the engines are a bit smaller. Dosoli indicated that sensors for acceleration, bank angle, front-wheel and GPS-speeds, along with front-wheel suspension stroke, are the more important parameters for real-time control in Kawasaki's MotoGP machine.

Controlled wheel spin can be a racer's tool for riding fast, but too much can result in a dramatic "high-side" which bucks the rider off the bike in dangerous fashion. By comparing front- and rear-wheel speeds with GPS-speed and engine rev-up, the bike can "see" when a muted response to throttle input is needed from the traction control system (TCS) in order to maintain grip. In fact, racers coming from production-class racing to MotoGP experience the impact of unprecedented tire grip, TCS, ride-by-wire, and rich sensor-based control. Several have commented on how much sooner they can get on the gas in a turn.

So, what does Kawasaki's electronics control system look like? Of course the team will never fully say, but Dosoli acknowledged an array of about 50 sensors on board, all communicating over multiplexed ECU/datalogger feeds with CAN busses. Thirty analog sensors join with four temperature monitors, exhaust oxygen level (lambda), and a host of other digital sensors. ECU control and datalogging can get to be a busy affair. For example, the "quick shifter" strain gauge on the foot shift lever--used for timing the ignition cut-out during clutchless gear changes--benefits from KHz sample rates to get it right.

Mounds of data also demand an Ethernet interface on the race bike to download information and upload new control programs in short order. But not all the work happens at the frenzied pace of the racetrack. Post-practice and qualifying hours are spent with engineers and technicians poring over much deeper and granular acquired data to improve setup and systems for the race, and the racing season.

Yamaha Tech3 tuning

The varying approaches to racing electronics within the GP campaign were highlighted in my visit with Andrew Griffith, data engineer for one of Yamaha's two factory MotoGP teams. Griffith began with a Motorsport Engineering degree from Swansea University in Wales, eventually distributing his graduate research project up and down the pit lane to land his job in MotoGP.

Griffith said there are teams using "in-house" ECUs, such as Honda and Ducati, but like Kawasaki, Yamaha Tech3 is using Magneti Marelli for engine control and 2D Systems for datalogging and sensory systems.

While sharing similarities with Kawasaki's approach, Griffith's team has gone to a full throttle-by-wire system. Physical cables from throttle to engine bay still exist--to provide the rider a conventional feel--but Yamaha has chosen to fully interject stepper-motor throttle body control between the rider's physical input and engine response.



Yamaha too employs a vast array of sensors on the motorcycle, along with accelerometers and gyros that track bike movement. GPS is on-board for data-tagging, but Griffith echoed Dosoli's comment about the tenuous nature of GPS as a reliable real-time control positioning input. To the larger point, Griffith spoke of the need for control-system simplicity because overly complex approaches breed their own set of safety issues.

Though "turned off for qualifying sessions," TCS and wheelie control are areas of focus for Yamaha during the race. The many other sensors onboard may play a role in TCS but "front- and rear-wheel speed differences are the key parameters you have to have to make it work" said Griffith. Since riders sometimes need to get a little loose, Griffith indicated it's more about controlling a window of allowable spin versus demanding full traction full-time.

To this end, Griffith and his team seem to appreciate the need for a rider to feel in control of the bike. When a racer's inputs sometimes contradict the data-implied optimums for settings and setup, an approach that delivers comfort and confidence over sterile computer-driven "optimization" is what's best.

Like its competitors, Yamaha can't stand still in development however. The team is employing a "new philosophy this year," but Griffith didn't reveal much more due to competitive issues. When asked about the development of a position-based, real-time, autonomous control system, the only response was a grin and the suggestion that this "was one possible direction" for the team. The silence spoke loudly enough to suggest such an approach is certainly on their minds if not on their motorcycles.

Suzuki lightning

A few pit stalls away, I visited with Tom O'Kane, an engineer who also targeted training in motorsports. O'Kane, like Griffith and Dosoli, was fortunate enough to "know what he wanted to do", going on to become crew chief for Suzuki's rider Chris Vermeulean under team technical director Shinichi Sahara, who set up the interview. As a riding enthusiast himself--Ducati twins being a favorite--O'Kane also shares a holistic view of man and machine when approaching his work.

Like the Kawsaki and Yamaha models, the Suzuki bikes are fully loaded with GPS, 3-axis accelerometers, 3-axis gyros and "30 plus" sensors over three CAN busses, all used for a mix of quick setup optimization and later, more detailed data analysis. 2D Systems is a repeat vendor to Suzuki for dashboard electronics, system sensors, and datalogging, while Mitsubishi supplies the ECU technology.

O'Kane was more direct on the question of location-based engine management. Knowledge of on-track position and the details of track characteristics can, in theory, allow for better autonomous control approaches and O'Kane went so far as to say that transponders around the track could be combined with time-distance interpolation to figure out bike location. However, he also said 6-axis monitoring (3-axis gyro + 3-axis accelerometers) "describes how things are moving, but is not used for inertial positioning" due to off-axis noise and drift in the sensors. Discussions of control system implementation and data sampling/filtering in use at Suzuki soon moved into the realm of "don't print that" but suffice it to say that things are getting quite scientific in places.



In the realm of traction control, O'Kane's comments mirrored the others', citing the "lower power/easier to correct" notion for 800-cc race bikes versus previous 990-cc machines. Still, the ECU counters fluctuations of the engine power curve to deliver linear and predictable response for maximum pilot confidence, all while leaving enough room for riders to get some rear wheel slip when they want it.
Despite all the technology being thrown at winning, O'Kane--like Griffith at Yamaha--said sometimes the data doesn't show the differences and they have to go by rider feel/input. Similar to Kawasaki, Suzuki also employs a "half-and-half" ride-by-wire system to retain a conventional throttle feel and give the rider a strong sense of connection to the machine. There is a constant pull between "feeling" and "measurement" and back-room sharing of knowledge between Suzuki's otherwise separate MotoGP and Superbike teams is one of several methods used to try and sort it all out.

2D Systems sensing sensibility

My last stop was with Dirk Debus, German co-founder of 2D Systems, major supplier of sensory, cockpit and data-logging systems to the MotoGP world. A club racer and computer science major from Hertz alma mater Universität Karlsruhe, Debus built a tinkerer's monitoring effort on his own racebikes into a business with co-founder Rainer Diebold.

As the man behind much of the sensory gear, Debus spoke of the monitoring challenges in an environment where 30-G levels of vibration noise risk overshadowing the 1-1.5-G signals of interest.



Open-systems approach

Debus reflected upon the need for an open-systems approach and a company emphasis to avoid a "monoculture of components" which are too specialized and too critical. In both sensors and cockpit display systems, 2D has to work with ECUs from all players--Magneti Marelli, Honda and Mitsubishi, among others--and flexibility in interface design is key to serving multiple teams.

A signal-to-noise ratio of 1:20 requires great care in component selection, along with clever software. When asked about whose accelerometers and gyros work best, Debus wouldn't name names, but indicated a reliance on German parts in his GP-sensor boxes.



I was amused when Debus answered the question of "Toughest thing to deal with?" with a quick reply: "The Riders!" As an engineer Debus can understandably struggle with the vagaries of human feedback but, as a rider himself, he can perhaps uniquely and legitimately get away with saying such things.

It was surprising to see a relatively small enterprise have such a presence in the well-heeled world of MotoGP. How did 2D Systems succeed in a land of giants? Again a quick response by Debus summed up the company's perceived edge nicely: "Knowledge, experience and passion!"

Good assets for almost any effort, really.

To the finish line

My thanks to the folks at Kawasaki, Suzuki, 2D Systems and Yamaha, who shared time to peel back some of the mystery of electronics technology in MotoGP. A nod also to Neil Spalding, author of the definitive book on MotoGP technology development, for help in formulating the right questions. If you want more technical detail, buy the gentleman's book--you can't go wrong. Finally, thanks to Dave Clegg, my motorcycle-riding (and engineering) colleague who helped with picture-taking and talking points. Collectively, these folks helped paint a crisper picture of what's going on with electronics engineering in the pinnacle of motorcycle racing. Rest assured, there are plenty of secrets unspoken in the massive technology push for MotoGP--maybe next year.

Rossi committed to carbon chassis






Marlboro Ducati's Valentino Rossi is committed to developing the carbon fibre chassis on his Desmosedici MotoGP bike and says there is no way he would want to swap back to an aluminium beam frame that Japanese manufacturers use.

The Doctor's target is to reach the same feeling with Alan Jenkins' design which basically uses the engine as a stressed member with a carbon swingarm attached to it and the shock. There is a new rear end on the 2012 bike, which Rossi loves, but it can't be transferred over.

"We have a chance to fix the bike without using the normal style like the Japanese. I don't want an aluminium chassis, no way. Our target is to reach the same feeling as the Deltabox with this type of bike," said Rossi, speaking at the Silverstone round.

"Already the 1000's rear is a different design but we cannot put it on the current bike, we try to create the same effect with the current bike which is more stability and better load at the front. We will not try a new front this year I don't think."

Rossi has also had to cope with two other factors this year: new Bridgestone tyres and the fact that, after having half of last year off, he is not at physically fit as he is used to being.

"I also need to modify my style for these tyres because during the last year the riding style of the top guys develop a lot. The spec tyre have less grip on the edge so you have to set the bike and try to use it in another way - less on the edge and I lose all last year my fitness so I am a little bit behind this type of riding."

Ducati GP12: technical analysis



Today, at Mugello, Valentino Rossi was back aboard the Ducati GP12, the machine with which he will contest next year's MotoGP championship. This was Vale's third time testing the new bike, after a first outing at Jerez in April, and another at Mugello in May, which demonstrates how much importance Borgo Panigale is placing on the 2012 season, where they hope to fight with Yamaha and Honda on equal terms.

But how did they build the GP12? Is it really revolutionary compared to the Desmosedicis we have become accustomed to? What we can say that it's... half a revolution. Ducati have decided to continue with the engine as a stressed member of the chassis, the central element on which the front suspension unit, the rear suspension unit, and the seat unit are attached. But the rear suspension layout, as we will soon see, has characteristics which are completely different to what we have seen since 2003.

Looking again at the big picture, it would have been nearly impossible for Ducati to implement a completely new project based on a design considerably different from what they have now. First, it's unlikely they would have had the necessary time to do so, but, more importantly, the use of the engine as a stressed member is one of the defining characteristics for the Italian brand's race machines. There are numerous strategic and commercial issues involved, since Ducati is essentially forced to differentiate itself from the large Japanese manufacturers, and they certainly can't afford "copy" their competitors. A small company challenging the Asian giants on equal terms is a recipe for disaster, which means that Ducati must, as Filippo Preziosi has always maintained, count on fresh and original ideas. At Borgo Panigale, therefore, they will continue down the current path, and even adapt the MotoGP concept to suit their new 1200cc Superbike.

To that same end, Rossi's comments on the Silverstone disaster were quite clear: a chassis with a conventional frame is not the panacea they are in need of. "The solution is not a new chassis with a more traditional design - the Doctor explained, this time dealing with a rather difficult patient - and this is supported by the data on the current design, which is actually quite comforting. It tells us that our bike can be competitive with the type of chassis we are using.


Returning now to the "revolutionary" aspects of the GP12, we have to focus our attention on the rear suspension layout. Beginning with the GP3 - the first MotoGP machine from Bologna - the rear end (swingarm and shock linkage) has always been attacked to the engine alone, as you can see in the design at attch. The top shock mount is on the swingarm, while the bottom mount - by way of the linkage - is on the engine, to which the swingarm itself also hinges on.

The GP12 breaks with this tradition, abandoning the so-called "full floating" rear in favor of a design with connects it with the rear chassis unit, or seat unit. An attachment point which actually replicates what is normally found on bikes with a traditional twin spar frame and rear crossmember. And so we see that, while the GP12 certainly contains the DNA of a Desmosedici, the engineers from Borgo Panigale have moved it slightly closer to a more traditional motorbike.

When you take a closer look at it, this solution is quite similar to that of the Yamaha M1; meaning that Valentino is likely to find that the GP12's rear end behaves and responds to adjustments in a way that he is already familiar with, and which could greatly facilitate his setup work.



When examining pictures from the recent tests, another aspect of the GP12 that jumps out is the design of the swingarm itself, which is now "inverted" (until now this design was not feasible due to the nature of the "full floating" attachment points); and this design brings significant advantages in terms of bike behavior. Compared to a more conventional swingarm, this design allows for a much lower focal point for the torsional forces applied to the unit under stress. In other words, when a swingarm is under load in a corner, it has a tendency to twist/bend, and an inverted swingarm allows this movement/flexing to take place at a point much closer to the ground, thus diminishing the resulting moment at the tire's contact patch. The end result is better performance and feel from the rear end of the bike.

Weather all this will be enough for the GP12 to better compete with the Honda and Yamaha, Ducati will only find out on July 4th. That is when the Japanese factories will test their 2012 prototypes at Mugello, and the Italian team will finally be able to compare lap times with their rivals.

The Trouble With The Ducati Desmosedici: An Exhaustive Analysis

*transalate sendiri!!!

Valentino Rossi's move to Ducati was a match made in marketing heaven, the combined selling power of the world's most famous motorcycle racer and the world's most iconic motorcycle brand would surely prove to be a veritable sales steamroller. Casey Stoner had already proven that the bike was capable of winning races - though it clearly had a problem with the front end - and with a seven-time MotoGP champion and the crew that helped him win those titles, success would be quick to come.

If sales of merchandise are anything to go by, then the move was definitely a success, MotoGP circuits coloring red as Rossi fans stocked up on Ducati gear, the red still tinged with Rossi's traditional yellow. But a look at the results sheets tells a different story altogether. Though the Italian is 5th in the championship standings (and just 2 points off 4th), Rossi has consistently crossed the finish line between 25 and 30 seconds after the winner took the checkered flag. So far, Rossi has taken just a single podium - arguably gifted to him, with Dani Pedrosa being taken out by Marco Simoncelli, and then Simoncelli being punished with a ride-through - and has found himself in the battle for 5th or 6th. By any measure, Rossi's move to Ducati must be counted a disaster, the combination a massive disappointment to fans, followers and even fellow riders.

Unsurprisingly, there has been fevered speculation about the cause of the problems, and whether it is down to the rider, the bike, or the combination of the two. Rossi fans point to his record, and the fact that he won a race in October of 2010, even while suffering with a damaged shoulder, only fixed after the end of the season. Yet Ducati fans, along with a contingent of Stoner fans, point out that Stoner was able to win on the previous incarnation of the machine (the GP10 the Australian raced last season was very similar, with one or two exceptions, to the GP11 which Rossi started the season off on), and so there can't have been that much wrong with the machine. Others postulate that it is not so much a single factor, but rather that the combination of Rossi's high-corner-speed style and the Ducati's flaky front end that is to blame, the Italian unable - or unwilling - to adopt Stoner's excessively aggressive corner entry style which allowed him to tame the Desmosedici.

So where does the truth lie? What is really wrong with the Ducati-Rossi combo? Is Rossi over the hill, or did Stoner make the Ducati look good, or is Rossi just not capable of adapting his style to the tricky Desmosedici? And if it is the bike, can Rossi's wily veteran crew chief Jeremy Burgess cure what ails the Ducati? We will go through the possible causes of the problem one factor at a time, but first, it may be helpful to identify exactly where the problem lies.

The Symptoms

Why is that neither Valentino Rossi nor Nicky Hayden have been able to get the Desmosedici to work? It all comes down to one thing: front-end feel. "The problem is in braking and entry," Rossi said at Mugello. "I don't have enough feeling from the front for corner entry like I want." The Ducati simply is not returning enough feedback from the front tire to the rider, nor providing enough grip from the front Bridgestone tire. "We have a lot of problems to put enough temperature into the tires," was Rossi's verdict at Assen, where very cool temperatures prevailed. At both Assen and Silverstone, Rossi had been forced to use the softer compound tire during practice, which helped by coming up to temperature a little more quickly, but as the soft front was only good for a few laps, it was never going to be an option for the race. The hotter temperatures at Mugello helped a bit, giving more feedback from the front, but still Rossi remained eight tenths of a second slower than the leading group.

Summarizing both Rossi's and Hayden's descriptions of the problem over the first half of the season, the front end of the Ducati feels vague and does not provide sufficient feedback, leaving both Marlboro Ducati riders with a lack of confidence in the front end. And the underlying cause of the lack of feel is the difficulty of getting the ultra-stiff Bridgestone tires up to temperature.

Is It The Rider?

The biggest variable which has changed between 2010 and 2011 is the departure of Casey Stoner and the arrival of Valentino Rossi. Though Rossi is now riding a heavily modified machine (the GP11.1, as it has been dubbed, is a destroked version of the 2012 Desmosedici, its capacity reduced to 800cc to make it legal for 2011), the bike he rode until Assen was not much changed from the bike Stoner left behind at Valencia in 2010. The bike had a modified triple clamp, a slightly different swingarm, and a slightly revised front chassis. The biggest changes have been in the field of electronics, Rossi and his crew helping to provide a much more user-friendly engine response package, introduced after Estoril.
So if Stoner made the Ducati work, then surely the problem must be with Rossi, right? Though that might appear to be the logical conclusion, that grossly oversimplifies a complicated situation. Just 9 months ago, with a weakened shoulder that left him struggling, Rossi was still capable of winning races and scoring regular podiums. He was poetry to watch, flowing over the Yamaha M1 and able to put it just about where he wanted. In the 11 races after returning from the leg he broke at Mugello, and still struggling with the shoulder injury he picked up in a training crash in April, Rossi was on the podium 7 times, including 1 win. Riders simply do not lose that kind of speed over the winter break, not unless they suffer a career-threatening injury.

From the moment he swung his leg over the Ducati, Rossi was immediately miles off the pace. He ended the two-day test 1.7 seconds off the pace of the fastest man, Jorge Lorenzo. Three days earlier, in the race, Rossi's fastest lap had been just a few hundredths slower than Lorenzo's. Worse still, Rossi looked nothing like himself on the bike. Several observers commented that it was if someone had sneaked into Rossi's motorhome, stolen his leathers and helmet, walked in through the back of the pits and onto the Ducati without anyone noticing he was not Rossi. At that first test in Valencia, Rossi looked like a journalist riding the bike, someone far less comfortable or able easing his way around the track.

Rossi was not the only rider to undergo an overnight transformation. Loris Capirossi jumped off the Rizla Suzuki and onto the Pramac Ducati and went nowhere, while Randy de Puniet has been transformed from the man who regularly scored top 6 results on the LCR Honda to a rider who can barely make it into the top 10 on the Pramac Desmosedici. With the Ducati's history of destroying riders' reputations - along with their self-confidence - Rossi is just another casualty in the long list that started with Marco Melandri.
The startling difference between Rossi's times from this year and those from last year are one clue that the problem is not with the rider. At Laguna Seca, where comparable temperatures prevailed between the 2010 and 2011 events, Rossi was 14 seconds slower this year than on the Yamaha. At the 2010 event, Rossi was still using crutches, the US round being only his second race since returning after breaking his leg at Mugello, some 8 weeks' beforehand. But the key piece of evidence that the problem is the bike and not the rider is the times of Nicky Hayden: the American was also 14 seconds slower at Laguna in 2011 than he was in 2010.

The Bike

So it appears we can safely rule out the problem being the rider. And if it isn't the rider, the problem must lie in the bike. Indeed, speculation and conjecture about where the problem lies has been more intense than ever this season, with everyone and their mother-in-law apparently having an opinion. The ideas around the Ducati's shortcomings seem to fall into three schools of thought, two centering around the chassis and another focusing on the engine, with the theories about the chassis being by far the most popular.

The favorite culprit is the use of carbon fiber to build a frame, the properties of the material being blamed for the lack of feel in the front end. The layout of the chassis is the next favorite among the pundits, the short subframe which joins the steering head to the engine being fingered as too small to provide sufficient flex for the front.

And the third, but far less favored option is the layout of the engine, the characteristic L-shaped 90° V4 forcing too much weight towards the rear. Let's go through these options one-by-one, and examine how much blame should be attributed to each.

A Brief History Of Motorcycle Chassis Design

Before we look at carbon fiber, a quick word on motorcycle chassis. Once upon a time, a frame was just some tubing that held the engine in place and connected the steering head to the swingarm. As tires improved and engine outputs increased, the forces involved in braking and accelerating started to overwhelm the tubular steel chassis, and frame builders started to make their frames stiffer. In the 1990s, chassis builders started to encounter the opposite problem: as their frames got stiffer and stiffer, the bike started chattering and vibrating, making handling terrible, especially when leaned over, when the suspension of a bike ceases to work, being in the wrong plane. And so the concept of flex was introduced, adding sufficient flexibility to allow the bike to absorb some of the bumps while leaned over, but still stiff enough to keep the chassis stable in a straight line and under braking. Since the late 1990s, and especially since the four-stroke era began, a huge amount of work has gone into engineering in exactly enough flexibility in specific areas, while retaining the stiffness in the planes where it is needed.

As tuneable flexibility has become increasingly important, the attractiveness of alternatives to aluminium has also grown. Traditional aluminium has the benefit of being light and easy to work with, but as MotoGP chassis designers push the limits, they also run into a few limitations. Engineering in flex is a matter of designing chassis elements with a specific thickness and shape, but the underlying properties of aluminium mean that at some point, achieving the precise amount of flexibility required means sacrifices strength. The way to get around this problem is to by making elements longer, allowing a mass (usually, the mass of the engine) to use the greater leverage provided by a longer element (such as an engine spar connecting the engine to the main chassis beam) to provide the flexibility without sacrificing rigidity.

When the rest of the world switched from perimeter steel tube frames to aluminium twin spar frames, Ducati took a different but still ingenious approach. Instead of wrapping the engine in aluminium box section, Ducati welded up short sections of light steel tubing to create a trellis frame. The advantages were that the chassis was relatively easy to tune, by changing the diameter and position of the individual tubing sections and redistributing the load and the flexibility, and Ducati persevered with the design for six years until they dropped it in favor of carbon fiber.

The downside to the trellis frame is that the trellis - a series of joined triangles - limited the amount of space available for the airbox. All those short, straight tubes meant the airbox had to be shoehorned in, restricting the airbox in both size and shape. Furthermore, the disadvantage of having the frame constructed from twenty or so short sections of steel tubing is that those twenty tubes require forty welds to join them all. Getting weld strength to a precise tolerance is a very tricky art at best, and the more there are, the more chance of variation. While still at Ducati, Casey Stoner said that even when he had identical setups on his two Desmosedicis, they would never feel exactly the same. Paddock rumor suggests that variation in stiffness between two supposedly identical steel trellis chassis could be large - as much as 15% - due in part to the problems of reproducing so many welds and so many parts to completely identical specifications.

Carbon Fiber - Too Stiff For Racing Motorcycles?

Hence Ducati's decision to go for carbon fiber (CF). The advantages over steel trellis are manifold: as CF is a composite, it can be easily molded to create whatever shape is required; its flexibility and stiffness can be almost infinitely tuned using a combination of fiber direction and thickness; it is incredibly light, with much greater strength than metals; and the stiffness and strength can be tuned to respond differently in different axes and directions, a more difficult trick with metals. Ducati's main reasons for choosing CF was the combination of stiffness, low weight and the ability to form the material into the shape required.

The Desmosedici's forward chassis section functions as a combined airbox and subframe: the subframe is required to be light and strong, while the airbox needs to be large enough to feed the Ducati's bellowing intakes as its 800cc motor spins at 20,000 rpm. By carefully calculating the desired stiffness in the different planes and axes - stiff enough to remain stable under hard braking, supple enough to flex from side to side to provide some suspension over bumps at full lean, all the while resisting torsion, or the urge to twist - the required combination of the number of layers of carbon fiber weave and the direction in which they are laid can be worked out. Once assembled, the subframe can be cured in an autoclave and sent to the team. Data returned from testing can then be integrated into the models used to create the existing subframe design, and a new iteration produced in the same way.



The claims by many that carbon fiber is too stiff to use in a motorcycle chassis can be put down to a common misunderstanding. CF can be made as stiff or as flexible as the designers want it to be, by varying the thickness and direction of the fibers in the weave. Its use is common in fishing rods, and for a demonstration of just how flexible CF can be, check out this video of a CF fishing rod being tested to breaking point.

The problem is not that CF is too stiff, but that the feedback it provides differs so completely from conventional aluminium. The property most often quoted is hysteresis, which in this instance, refers to the rate at which absorbed energy is returned. One of the benefits of CF is the fact that it can be made to damp vibration, its hysteresis meaning that the energy absorbed from an input (such as striking a bump) is released in a much more controlled fashion. Tap an aluminium tube and it rings like a bell; tap a CF tube and it emits a dull thud.

This is a property that Ducati had hoped would help them solve the problem of chatter (or extreme vibration over bumps) but it had an unintended side effect. Just as with the original attempts at using carbon fiber for chassis, starting with the Cagiva back in 1990, the damping also removes some of the feel from the front end. When used to build swingarms - as Aprilia had been doing for their 250cc racers for several years - this damping helps remove unwanted vibration, but at the front of the bike, that vibration also contains valuable information. As Guy Coulon once explained to me on the subject of unconventional front suspension systems, what is required of a racing motorcycle is that the information from the tarmac should pass directly into the rider's brain with as little interference or loss of data as possible. Any system which removes or alters that information means that the rider has to learn to interpret the feedback almost from scratch. All of the experience gained in his many years of racing is of little value in interpreting what he is feeling.

This is what caused the Cagiva to fail back in the early 1990s. The riders, brought up on a generation of steel and aluminium chassis, simply could not understand the feedback they were receiving from the machine. And this seems to be at least one part of the problem with the Ducati Desmosedici: the carbon fiber subframe connecting the front forks to the front of the engine may be damping the vibrations too much, reducing the amount of information traveling from the front tire up into the rider's brain. Alternatively, it may be returning too much information, providing more feedback than most riders are used to receiving. Filtering out this new (and not necessarily useful) information may be what is confusing the riders about the feel.

As we said earlier, the underlying problem of the Ducati is the difficulty the riders have in getting it up to temperature. The stiffness of the CF chassis may not be the problem here, but the feedback from the chassis could make it harder for the riders to push the tire hard enough to start working.

So is the choice of carbon fiber the main cause of Ducati's problems? Looking at the theoretical benefits of the material it is hard to say that it is. There could be an issue where the feel of a CF chassis is sufficiently different to traditional aluminium that it is hard for riders with many years' experience of metal frames to interpret and understand. But with Rossi known more for his adaptability than for his rigid adherence to a single style, this does not seem like an insurmountable candidate. So let us examine the next candidate.

The Mini-Frame - Less Flex Than A Twin Spar

If it's not the material, perhaps it is the amount of material being used. The major difference between the Desmosedici and the Yamaha, Honda and Suzuki is not so much the use of carbon fiber, but rather the use of the engine as a stressed member of the chassis. Where the Japanese machines have long aluminium beams joining the headstock to the swingarm, the Ducati has a short, boxy section bolted on to the cylinder heads of the two banks of cylinders that comprise Ducati's 90° V4. The mounting is as direct as possible, with the mounting points placed near to the headstock.
The advantage of this construction is that it uses the stiffness of the engine casings to be used as an integral part of the chassis, and it allows the chassis to be made much lighter. With both the front subframe and rear swingarm attaching directly to the engine, there is little superfluous material around. This makes it possible to keep the bike very narrow (there is no perimeter frame snaking around the engine), as well as using the stiffness of the engine to maintain stability under braking. Again, by integrating the airbox into the subframe, another extraneous part can be discarded and the weight of the bike kept down.



Criticism of the design focuses on the shortness of the parts involved, and the complications that adds in obtaining the desired degree of flexibility. The words of Masao Furusawa, the design genius behind Yamaha's M1, are often cited, about the need for the chassis to bend like a tree. Longer chassis sections create a longer lever, and allow flexibility to be created much more precisely. To illustrate the argument, take a long, thin object - such as a cane, or a wooden ruler - and try to bend by pushing down at both ends. The object should bend like a reed. Now put your hands just a couple of inches apart and try to bend the object again: it's almost impossible, at least not without snapping the object. The long engine mounting spars on Yamaha's M1 are a case in point, their length aimed at absorbing bumps while the bike is leaned over.
The counter-argument to this criticism is that the use of carbon fiber makes using longer chassis elements unnecessary. The very programmable nature of CF - the mixture of layers, direction, resin and curing - means that it should be possible to exactly replicate the effect of a long aluminium chassis spar merely by varying the nature of the carbon fiber used. Long sections may make things easier when building frames in aluminium, but carbon fiber dispenses with all that.

Though CF is undeniably an incredibly versatile material, there may still be some merit in the criticism. Having such a short subframe also means that the engine has to transmit a lot of the load. The engine is significantly stiffer than the chassis - it has, after all, to contain and dissipate 230-odd horsepower and deliver it to the back wheel without shaking itself apart. What this means is that the entire chassis assembly consists of two separate parts of completely different stiffness. The more flexible front subframe - complete with engineered flex to aid in absorbing bumps at extreme lean angles - is connected to a rigid engine with almost no flex at all. The central part of the Desmosedici has no flex, while the front subframe and the rear swingarm do.

On a more traditional twin spar chassis, the loads are carried from the front of the bike to the rear through aluminium beams connecting the headstock to the swingarm. The CF subframe may be engineered to provide the same amount of flex as a traditional twin spar, but the two ally beams on the twin spar flex much closer to the center of the bike. Instead of having a rigid center and a more flexible front, a twin spar chassis has a long section which can flex in the center of the bike. Added to the different forces created by attaching the engine using long front engine mounts, the feel of the Ducati will be completely different to a Japanese machine.
There have been a host of clues recently that Ducati are already working on an aluminium twin spar chassis for the GP11 - or possibly the GP11.1 - after a lot of pressure from Rossi and his crew chief Jeremy Burgess.

A twin spar chassis could make its debut as early as Brno (though it is more probable to make its first public appearance at Valencia) with signs coming from several sources that big things are afoot at Ducati.

But the twin spar may not be the panacea that Rossi (and his legion of fans) are hoping for. As team manager and test rider Vito Guareschi pointed out to a gaggle of Italian journalists and myself, building a twin spar frame means fighting the Japanese on their own territory. Both Yamaha and Honda have nearly thirty years of experience of building these frames; Ducati has absolutely none. Though a lot of the knowledge is already available, the devil - and the potential for victory - is in the detail, the final refinements giving the last couple of tenths that make the difference between being competitive and running around in 7th. Ultimately, Ducati - with a lot of pressure from Rossi and from main sponsor Marlboro - may feel they have nothing to lose, and gamble it all on an aluminium twin spar chassis.

Will it help, though? Using a traditional twin spar chassis may provide more feel at the front, and it may make the riders feel a lot more comfortable on the bike. What it won't necessarily do is generate a lot of heat in the front end, which brings us to the next subject: Ducati's sacred L4 configuration.

The L4 - Bad Packaging And Poor Weight Transfer

Ask anyone with even a passing interest in motorcycling what engine a Ducati uses and they will tell you without hesitation that it is a 90° V twin, also called an L twin, because the right angle between the two cylinders makes the configuration look like the letter L. The Bologna factory has been building engines in this configuration for 40 years now, since switching from smaller capacity singles to V twins at the start of the 1970s.

So when Ducati decided to enter MotoGP, they naturally attempted to retain the iconic engine design which has been a key selling point for so many years. Filippo Preziosi was quick to understand that a twin would never be able to produce the horsepower needed to compete in the series, and so concentrated instead on building a four-cylinder engine, built to resemble the 90° L twin as closely as possible. Almost as an act of penance for the extra set of cylinders, the initial plan was for the Desmosedici to use a "twin pulse" or big bang firing order, with the cylinders in each bank of cylinders firing simultaneously, to make the bike sound (and behave) more like a twin. Problems handling the power such a configuration produced meant that Ducati had to switch to a "four pulse" or screamer firing order, each cylinder firing separately, but since then, the factory has oscillated between the two firing orders.
The major benefit of a 90° angle between the cylinders is primary balance, where the motion of each piston in the V is balanced against the other piston. As one piston reaches top dead center, the other is in the middle of its stroke, maintaining its momentum and damping the change in kinetic energy as the first piston switches from upwards to downwards motion. The mechanical balance of the L configuration means that it does not require a large balance shaft to damp the vibrations of the engine, saving power. Balance shafts cost power to drive.

But the biggest problem of the L4 configuration is its size and layout. In the modern era of MotoGP, much of the focus has been on keeping the mass of the bike as centralized as possible. The benefit of centralizing mass is that changing the setup of the bike - its weight distribution, rider position, suspension changes - can be more refined and more predictable. Knowing where all of the mass is makes it easier to calculate how to move it around to achieve the desired effect at a particular track.

The main thrust of mass centralization has been in engine layouts: Suzuki's GSV-R uses a 65° V4 engine, Honda's RC212V uses a 72° V4, and Yamaha's M1 uses an inline 4 to make the engine even more compact, sacrificing a little bit of width for more centralization of mass. Behind the crankshaft, gearboxes are stacked, the rows of gears transferring power from the crankshaft to the rear wheel folded up into a V to shorten the length of the gearbox and keep the mass even closer to the engine's overall center of mass.
The compact engine layouts have a secondary benefit as well: with the engine taking up less space, fuel tanks have migrated to be located underneath the rider's seat, placing that mass (which disappears as the fuel is burned off during the race) close to the center as well. A compact engine gives designers the freedom to place other heavy objects - including the rider - in a range of locations around the bike, to help them achieve whatever goals they may have set themselves.

And here's where Ducati's L4 falls down. The angle between the two cylinder banks makes the engine much longer than its rivals, leaving a large space between the cylinder banks which is filled only with the throttle bodies and airbox/subframe. While the front cylinder bank protrudes through a cutout in the radiators to almost touch the front wheel, the rear cylinder bank slopes back and sits right where Yamaha has its fuel tank.

The 90° angle between the cylinders forces the front cylinders to angled forward much more than the narrower angle Honda. Visual estimates (the exact data involved is highly sensitive and impossible to obtain) suggest that the front cylinder bank of the Ducati is at 70° from the vertical, while Honda's RC212V is at just 45°. This means that the Honda engine can be moved much further forward and closer to the front wheel than the Ducati, allowing the Honda's chassis designers more freedom in placing the engine. The 18° difference in V angle between the Ducati and the Honda also equates to cylinder banks that are roughly 15% further apart, making the engine correspondingly longer. Move the Desmosedici engine further forward, and you foul the front wheel; move it further back and you drastically shorten the swingarm.

The physical size of the Desmosedici engine - or rather, it's rather rangy layout - means that much of the mass of the bike is further back than its rivals, with less freedom for changing weight distribution, especially at the design stage. This difficulty in moving weight distribution is one of the prime candidates for the difficulty the riders have for getting the Desmosedici's front tire up to temperature. While the bike may feel fine and the weight distribution look good on paper, the way the weight transfers under braking and acceleration is different, and this could be what is preventing the riders from getting heat into the tire.

There are several major clues that this is exactly what the problem is with the Desmosedici. Throughout their struggles with the Ducati, Rossi and his vastly experienced - and multiple world championship winning - crew have experimented with some fairly drastic changes to the weight distribution. At Mugello, they raised the center of gravity by 20mm, a vast amount in a world where normally parameters are changed a millimeter at a time. At Laguna Seca, they tried another change, shifting the weight further back and leaving Rossi's bike looking more like a chopper than a racing motorcycle.

Indeed, the main rationale behind the switch from the GP11 originally fielded for the 2011 season and the heavily revised GP11.1 is that they could raise the center of mass much more without making the rear pump, a problem which the original design with the top-brace swingarm suffered from, and familiar to anyone who watched Casey Stoner coming out of corners on the GP9 and GP10 in previous years.

What Works In WSBK Won't Work In MotoGP

But if the L configuration is the problem, how come it works in World Superbikes? Ducati has dominated the WSBK championship over the years, and Carlos Checa is well on his way to wrapping up another title for Ducati aboard the 1198R, fitted with a 90° L-twin engine. So how can a design that is ripping up WSBK suddenly be such a disadvantage in MotoGP?

The answer to that question is to be found in the underlying cause of the MotoGP machine's problems: the tires. The World Superbike series use Pirellis as the spec tire, and the Pirellis are a completely different beast. The construction of the Pirellis is much less stiff, making generating heat in the tires a much simpler task. With a front that sticks and provides feedback, the 1198 responds perfectly, and the L twin engine is much kinder to the rear tire than the four cylinders, allowing Ducati's WSBK machine to be competitive.

The Bridgestones, on the other hand, have an incredibly stiff carcass, built to handle the stresses created by Grand Prix machinery, from the powerful engines, stiff chassis and carbon brakes. Once the tires are up to temperature, they offer astounding levels of grip and feedback, allowing unbelievable performance. Outside of their optimal temperature range, they are much less forgiving, giving little feedback and making the amount of grip available difficult to judge. The L4 being used by Ducati is a prime candidate for the Desmosedici's inability to get the front Bridgestone tires up to temperature.

The irony is that Ducati's early adoption of the Bridgestone tires created a highly-productive collaboration between the two parties. With a lot of input into the development direction, Bridgestone created tires that worked well with the Desmosedici. But as other teams and factories started to switch to the Bridgestones, Ducati's influence became less important, and once the spec tire was introduced, the input from Ducati became just one of the many data sources that Bridgestone used to develop the tires. With data from three Japanese factories using a conventional aluminium chassis and an engine sitting taller and further forward in the frame than the Ducati, the Desmosedici's unconventional design has become less suited to the Bridgestones.

This also underlines exactly how important tires have become since the introduction of the single tire rule. By limiting the design and construction of the available tires to just two compounds (soon to be three compounds, but still), the room to modify the behavior of the bikes using the tires has completely disappeared. Right now, the key to building a competitive MotoGP machine is to understand the characteristics of the spec Bridgestone tires, and designing a motorcycle to suit them, exploiting their strengths and circumventing their weakness. This is a process that Yamaha and Honda appear to have adapted to much more quickly than Ducati has.

What About The GP12?

When Filippo Preziosi suggested to Valentino Rossi that he could modify the GP12 to make it legal under this year's rules, Rossi jumped at the chance. When testing the GP12, Rossi felt the bike responded much better, and he had fewer problems with the front than he had with the 800. However, once the GP11.1 (the GP12 destroked and made legal for 2011) was introduced at Assen, the old problems returned, Rossi still left complaining of a lack of feel in the front end.

How can this be? How can two identical bikes, identical except for the length of the connecting rods, the position of the crank pins and the swept volume of the engines, behave so differently? The answer lies in the different ways in which the 800 and the 1000 (or whatever capacity the GP12 happens to be) need to be ridden. The 800cc MotoGP machines all need to carry as much corner speed as possible, which means the bike is spending a lot of time at or near maximum lean. This is exactly the point where feedback from the front end is crucial, the ability to feel what the front tire is doing. The GP12, both Valentino Rossi and Nicky Hayden have said, can be ridden using the torque more; corner entry is less crucial, and the available torque means gives the rider more options coming out of the corner. The bike is spending less time on its ear, in that critical zone where front end feel is so crucial.

If the good news is that the 1000 will be spending less time in its weakest area, the bad news is that the problem is still there. The GP12 suffers from a lack of front end feel as much as the GP11 or GP11.1, it's just that it will be easier to ride around it. The new chassis, the bigger engine, will not magically cure the Ducati's ills. The GP12 may not suffer as badly as the GP11, but it will still have problems contending with the Honda and the Yamaha.

Fixing The Ducati

While the whole world and their cousin-in-law concentrate on the Ducati's use of carbon fiber and their minimalistic subframe which functions as a chassis, the problem may lie elsewhere. If the rumors are true, an aluminium twin spar frame could soon be on its way to the Ducati garage, possibly as early as Brno.

All of Bologna, all of Tavullia, all of the Valentino Rossi - and indeed, Nicky Hayden - fans around the world will be praying that this is the solution, and Rossi can start to compete once again. If it doesn't, then Ducati is in an even bigger hole than they are now.

From all that I have learned in speaking to engineers - or rather, listening, and then shamelessly stealing their ideas, for which they have my eternal gratitude - Ducati's problems are not fundamentally down to their minimalistic chassis design, and probably only partially due to their use of carbon fiber.

The concept of combining the two - a small subframe made of carbon fiber, tuned to provided optimum flex - is basically sound, though it clearly has a few problems. The biggest being the feedback provided by carbon fiber, is fundamentally and confusingly different from that provided by an aluminium twin spar design. If riders can learn to understand the information being returned from the carbon fiber chassis, and the engineers can design the CF to produce the desired feedback, then this avenue could provide options well worth exploring. It may also offer Ducati's best hope of competing, as any move to use a twin spar chassis leaves them short of the twenty-odd years of experience the Japanese manufacturers already have.

The much bigger problem, in my view, is the layout of the engine. It is physically large, the 90° L4 layout making the engine long, and placing the cylinder banks in awkward locations when packaging a racing motorcycle. The size and shape of the engine makes compromises on layout inevitable, and precisely these compromises are what are preventing the Ducati from generating the necessary load in the ultra-stiff front Bridgestone tire, and leaving the front end of the bike feeling vague. With no confidence in the front end, neither Valentino Rossi nor Nicky Hayden - nor indeed any of the satellite Ducati riders - can push the bike to the extent needed to be competitive.

Abandoning the L would be the biggest step Ducati could make towards becoming competitive again. It would open up avenues which the current layout make it impossible to explore. The weight distribution would be much more flexible, giving Rossi, Burgess and co. more options to explore. A more compact V or even an inline 4 layout could turn around Ducati's prospects.

Rossi vs. Ducati

Of course, this means abandoning forty years of history, and a layout which has become part of the Ducati legend. If it were to fail, Ducati would have lost both its reputation as a manufacturer of fast motorcycles, and sacrificed a key part of its iconic brand identity. If it succeeds, the question is whether the Ducatisti will feel that sacrificing their heritage is worth the return in competitiveness.
It all boils down to two simple questions. Does Valentino Rossi's failure on the Ducati more harmful to Rossi or to Ducati? And would changing Ducati's design philosophy - potentially abandoning the iconic L configuration - hurt Ducati's long-term prospects more than allowing Rossi to continue failing, and risk losing him to another manufacturer?

To my mind, there is no debate. Ducati's exclusivity is built to a large extent on sporting success. Failure in MotoGP is simply not an option, the worst of all possible worlds. If Ducati is to exploit the strength of their own brand - and especially the selling power of Valentino Rossi - they need Rossi to be winning, or at least on the podium week in and week out. The MotoGP bikes are seen as so far removed from Ducati's street machines that the engine configuration - or for that matter, the chassis layout - is irrelevant. Using an L twin may be a big deal for Ducati's World Superbike effort, as there they are racing the machines that they are trying to sell. But exactly how many degrees apart the Desmosedici GP11's cylinders are has no bearing on the purchasing decisions of prospective Ducati customers. Having Rossi be successful is. If Rossi fails, Ducati fails, leaving them either to find another rider who can ride around the Desmosedici's problems, or pull out of MotoGP altogether and focus on World Superbikes.

That final scenario is all too realistic. Ducati has survived in MotoGP thanks to the generosity of Marlboro's parent company Phillip Morris. Hiring Valentino Rossi is exactly the kind of high-profile coup that the tobacco giant loves. Having him fail miserably is exactly the kind of thing that Phillip Morris hates. If Marlboro believes the Ducati project is fundamentally flawed and that Ducati Corse is unwilling or unable to fix it, they will be gone, off to find another avenue for the promotion of their brand. With Yamaha without a title sponsor, and a long history with the Marlboro brand, Phillip Morris should have no trouble in finding another partner in MotoGP.

awww...fully carbon...balut 1 moto mcm ni cun gilerr lahhh!!!

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Ducati looks to aluminum for handling fix. After one practice session at Motorland Aragon in Spain, Valentino Rossi was eighth-quickest on Ducati’s latest attempt to give him and teammate Nicky Hayden more front-end feedback. Two years ago, Ducati adopted a new design direction, abandoning its traditional steel-tube “trellis” chassis in favor of a new Vincent-like construction using carbon fiber. In this new scheme, the engine became the main structural member, with swingarm and rear-suspension linkage attaching directly and only to it. Joining the steering head to the engine Vee in front was a pyramidal black box of carbon fiber that also performed the function of engine airbox. This construction would save considerable weight. During his time as a Ducati factory rider, Casey Stoner (now leading the championship on a Repsol Honda) had said that on the trellis chassis, he could not “hit the same point on the track two laps in a row.” As Stoner had been world champion on such a chassis in 2007, this suggested that although its flexibility gave it good front-end “feel” (that is, it gave warning as the front tire neared the limit of its grip), flexibility in other directions made steering imprecise. This movement had also prevented Ducati engineers from sliding the engine as far forward as they would like, because during braking, the front tire would be deflected to the rear, threatening to rub on the cambox of the front cylinders. The greater stiffness of carbon fiber would prevent much of this flexure, allowing a more forward engine location. When the carbon bike was raced, Stoner found it unpredictable. He said of it that, “You push, and it’s okay. You push some more, and it’s still okay. Then you push again and you’re in the gravel—no warning.” The flexure of a normal front end acts like a short-travel suspension when the bike is leaned over, keeping the tire in contact with small irregularities and able to recover grip after skipping over the top of a slightly bigger irregularity. But if you take that flexure away and then hit that bigger irregularity, your front tire just hops into space and goes away, dumping you into the gravel. Yamaha’s YZR-M1 had this same syndrome in 2003. Riders were falling because the bike was not giving them the feedback they needed to know how close they were to the limit of front grip. If you are camping on the rim of the Grand Canyon, do you get up in the dark of night to go for a walk? No, because nothing can tell you how close you are to the edge. This is why both of Ducati’s current riders, Rossi and Hayden, have spent most of this season well back from the edge in disappointing positions like the eighth and seventh spots they occupied on Friday. Well, how about “just goin’ for it?” I mean, these guys are racers, right? Yes, but they aren’t stupid. There is no glory in crashing a bunch of priceless GP bikes. Okay, but didn’t Stoner win races on it, even if he didn’t take the championship? Yes, but his riding style has the versatility to take some pressure off the front by steering with the back. So far, Ducati has tried variations in the design of the carbon-fiber box, adding bits of flexibility where possible by moving the front-wheel bearings closer to each other and changing steering-head bearings from rollers to balls. Ball bearings are quite elastic, as even hard steel deforms under pressure. The initial point contacts of the balls on the races become bigger and bigger circular contacts as load is applied. Rossi’s crew chief, Jeremy Burgess, has noted that in the 10-inch length of Ducati’s rigid carbon-fiber box, it is next to impossible to design in much lateral flexibility. That requires something a lot closer to the twin aluminum chassis beams used by all other teams. Such beams, being deeper than they are thick, are able to flex laterally somewhat without allowing the steering head to twist or bend. Therefore, this weekend, Rossi is testing a bike built around this idea. In photographs, you can see something like aluminum side beams extending up toward the steering head. These would presumably attach to existing hard points on the engine but are far enough back to allow the desired lateral flexure of the beams. Why is Rossi still in eighth if this test chassis (made by FTR in England) is so hot? The chassis has been in Ducati’s hands for roughly a week, and finding a setup takes more than an hour. Ducati’s second problem—its rearward weight bias, making it hard to finish the corner—is another matter.