MotoGP History, the First 4-strokes

As it happens, despite the fact that the smart money was on Honda to have developed at least half a dozen different 4-stroke prototypes. It was Yamaha who broke cover first by announcing that at the end of the 2000 season, and following, the deduction of points from Noriyuki Haga, effectively costing him the WSB title, they'd considered withdrawing from the series. At the time, they were conspicuous in releasing glimpses of a prototype they had been working on and secreting favorable images and comments of their GP works riders. Biaggi and Checa testing on it.

These comments were even more pointedly related to their road range and the inference that whatever slight advantage the gixer 1000 might have had over their stalwart R1 for a season, their GP1 derived R1 for 2002 onward was going to blow it into the kitty litter.

But for a company known for its technical daring and which eschewed the often conservative. Honda evolutionary policy, for once they seemed to have erred on the side of caution. There are several reasons for this. Firstly, risk. To develop a completely new format at this level and expect to win against the most awesome racing machines in the universe is a risk Honda paid for twice with a bloody nose.
Don't forget, the new breed of 4-stroke bikes has to beat not only other manufacturers machines but , almost as importantly, bikes from its own stable. Secondly cost. To continue with the same format as their previously successful 4-stroke race bikes in whatever series, obviously gives Yamaha good base point, both technologically and financially. And thirdly, image, Yamaha makes transverse four sports bike and looks like it will continue to do so cementing the relationship between race and road ever more closely.

By Spring this year, testing was already well under way with the new 1000cc in-line 4-stroke (codenamed the M1) both in Japan, at Sepang and Mugello, and involving not just indigenous factory test riders, but Biaggi, Checa and, of course, the most famous development rider of them all, John Kocinski (actually he just broke his arm riding the very same new bike when a hose sprang a leak and sprayed coolant on the rear tire)

The man in charge of the project is the track-suit wearing Masahiko Nakajima. As head of GP500 racing, the presided over Yamaha's netting of the manufacturer's crown last season and he knows the importance of balance, citing it as the number one priority in the development of the bike. It's for this reason Yamaha wanted to stick so closely to the 500YZR proportions, and why they felt a transverse 4 was the way to go. "We considered other formats such as a V4, but in 4-stroke form the in-line 4 corresponded best with the parameters of the chassis we wanted to use," confirmed Nakajima. As such, the new engine was designed to fit within the package rather than the chassis designed to fit round the engine, and though the regs demand that the 4-stroke carry an extra 15kilo weight over the 2-strokes 130kilo minimum, it was the team's intention to replicate the feel and balance of the current GP 2-stroke as far as possible.

Nakajima also points out that the crucial variable in this new formula is going to be tire life and, as such, developing and engine that's going to look after the rubber race long. After all, current WSB 4-strokes are already pushing the limits of tire longevity and the GP version will necessarily mean more power, torque and weight. With over 200 horsepower on tap, the objective is to produce a perfectly linear delivery, making the bike as neutral and user-friendly as possible and, it's claimed, obviating the need for traction control. Yamaha has been working closely with Michelin throughout its test program and both groups of technicians understand the modern idiom of utilizing wheel-spin to steer effectively. It's for this reason that the company has also been moving inexorable toward the 16,5 inch rim and away from the old 17 inch formula, the smaller fitment permitting a grater contact patch. If nothing else the prospects for the fours are of a wheel-spinning spectacle.

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