American Edwards and Haga will team up for Aprilia for 2003

The 2003 MotoGP season promises to be the best we have seen in a long while, if not ever. For the first time, we will see a field full of 990cc four-strokes without one solitary two-stroke. It's just over 30 years ago that Jack Findlay won a 500cc race on a two stroke Suzuki twin, the first non four-stroke win in the top class, and slightly less time since Jarno Saarinen became the first man to win a 500 race on a four-cylinder two stroke—Yamaha's across the frame engined machine. Those wins signalled end of the classic four-stroke era and ushered in the square-four then V4 machines that dominated the top class until last year. The way the new generation instantly overwhelmed the old took many people by surprise. The question now has to be, 'How much faster can they go?'

Just over a year ago at the HRC test in Malaysia, Valentino Rossi did a race simulation on the as yet unraced RCV211V. According to leaked information, he bettered the race record by something like 45 seconds. When racing started the V5 Honda was obviously the best motorcycle out there—but it wasn't 45 seconds a race better. The fact that the V5 was only beaten twice, and one of those was because of tire failure, disguised the fact that the Yamaha M1 was, by common consent, the equal of the RCV at the end of 2002. The Honda appeared to have changed very little, whereas the Yamaha was a completely different machine, forced to undergo a total reincarnation by the speed of the RCV.

The RC211V only underwent one noticeable change during the '02 season: the 'ram air' induction first seen at the Czech GP. This, according to mechanics, wasn't really an improvement and they treated it more as a tuning part for the rest of the season, using it where they thought the peakier power it produced by increasing pressure in the airbox at high speeds might be useful. Rossi, tall rider that he is, started off by using the system's slightly bigger fairing but not the ram air ducts. However, there was one unseen change at Brno that had ramifications serious enough to inflict Honda's first defeat of the year. The speed of Biaggi and the Yamaha in qualifying prompted Honda into using some of the power they'd held in reserve since that Sepang test. Overnight HRC decided to go up two stages on the engine-management chips producing enough extra power to shred Rossi's tire and hand victory to Biaggi and Yamaha. Michelin got the blame at the time, with the slipper clutch being implicated later. Information about the power increase emerged later in the season, along with the suggestion that Michelin could have coped with one level of power-up overnight but needed a bit more time to cope with two. Here was an explanation for those pre-season reports from Malaysia. That was when Honda took all the safety nets away and ran the RCV at maximum potential.

Mad Max Biaggi is on a Honda in 2003, he swears revenge

So is the RCV211 the perfect motorcycle? Not quite. It did have problems in its first year and not just with the slipper clutch. There were times when Rossi especially was complaining about lack of sidegrip and his race engineer offered the opinion that from the front wheel to the swing-arm pivot they had an almost perfect motorcycle. His opinion of the remainder is not fit to print. Obviously, he was exaggerating for effect, but there is no doubt the rear suspension of the RC211V is an area Honda are slightly defensive about. Remember that the new generation Unit Pro-Link places nearly all the suspension system under the swingingarm, the shock itself is not attached to the main frame and the whole mechanism is attached to the chassis at just one point. This radical re-think of conventional practice was forced on Honda by their decision to prioritise the position of the airbox and fuel tank, thus putting them in the space normally occupied by the suspension linkage. Some team members said at the start of the year that top men from HRC had reassured them that they always had an option to go back to a conventional system if the new layout didn't work. After all, conventional wisdom has it that the objective is to minimise unsprung weight, yet here was a way of effectively maximising it. By the end of the season, the top men were pointing out that there was 20 years of experience with the original design and they were still learning about the new design. Obviously, there was never a chance of the design being altered once the new CBR600RR appeared with an almost identical system to the RCV.

Some engineers think the RCV's Pro-Link has had one pleasant side-effect, helping to minimize chatter by not feeding big shock loadings into the chassis at the start of suspension movement. Another theory is that the extra weight may alter the resonant frequency of the assembly so it does not promote chatter. This is the area in which a lot of research is being done, chatter and its effects correlate closely to rider 'feel' for what the machine is doing. Obviously, it's hard to pin down what influences rider 'feel' and one HRC engineer told me that it is half engineering and half intuition. The same applies to chassis flex. The RCV's frame, we have been told officially, is much stiffer torsionally than the old NSR frame but not that much stiffer laterally. It is thought that this allows the chassis, especially the swingarm to act like suspension when the bike is at full lean and the Pro-Link suspension is at is least effective.

This is the area that the factories with well-sorted motorcycles will be looking at, and that means Honda and Yamaha. The very interesting M1-based prototype—known as the M6—that we saw Norrick Abe on pre-season is obviously looking for some radical solutions to these problems and appears to be engineered specifically not to feed big loadings into the main chassis. Perhaps the Yamaha men agree with Honda about the advantages of the new Pro-Link? You can forget simple stiffness being the issue, engineers are now also looking at the natural frequency at which various assemblies vibrate and whether they have any relationship to or effect on chatter. At least you can see that Abe's Yamaha is different from the side of the track. From that vantage point the 2003 Honda looks just like the '02 bike but the frame is completely redesigned. It may be that they have sacrificed some of the perfect feel at the front end - how could Rossi have backed the bike into corners so radically if the front wasn't perfect?—for more feel from the rear, but you can bet that it is relative stiffness and the natural frequency of vibration of components like the swinging-arm that have driven these changes.

Next: Factory by Factory Analysis

ENDS

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