Who can fail to be excited by the prospect of Honda's new V-five Grand Prix racer for 2002? Certainly nobody who has ever heard the last five-cylinder racer - the 125 of 1965/6, ridden to championship victory over the Yamaha and Suzuki two-strokes by Swiss Luigi Taveri. This landmark bike was more important than Guzzi's V-eight, because it was successful. And astonishing. Essentially two-and-a-half of their 50cc twins joined end to end, revving to more than 20,000 rpm, and with three jaunty pipes on one side and two on the other, it made a sound unrivalled before or since for volume, let alone symphonic complexity. I have a picture of Taveri warming it up pre-race, surrounded by gob-smacked fans, all covering their ears - Moby should sample it, for one of those dire "Motorbikin" compilation albums that sink without trace from time to time. That was, as far as I can establish, the first-ever five-cylinder bike ever built. The second ever will be very different. That little monster had all five cylinders in line. The much bigger new GP four-stroke (maximum capacity 990cc) cuts crankshaft length with the V-configuration.

Five cylinder engines are common enough in cars (Audi and Volvo, among others), and even to be found behind the back seats of your average London bus. History proves, however, that it is not an obvious choice for a motorcycle.

Why have Honda chosen it? Having resumed their usual tight-lipped manner since the high-level lead, we are left to guess. And knowing the company, one answer is: Because they can. (To twist the famous words of Everest climber Mallory: Because it wasn't there.)

The other reason is obvious - the more cylinders you have, the more valve area you liberate, and the more power you make - until you reach a limit imposed by internal friction at about 12 cylinders. Note how many F1 cars are V-10s - currently the most effective compromise between bulk, friction and power.

I was surprised, because I thought five cylinders took them into the highest minimum weight category. I was wrong; it doesn't. But if I'm vague. Doubtless you readers also need reminding of the proposed rules on crucial weight limits. 500cc two-strokes stay at 100/115/130 kg. (220/253/286 pounds) for two/three/four-cylinder motors; 990cc four-strokes come in at 135 kg. (297 pounds) for twins and triples, 145 (319 pounds) for fours and fives, 155 (341 pounds) or six or more cylinders. (Use of oval pistons adds 22 pounds to the limit, though 155 kg. — 341 pounds - remains the maximum.)

Weight limits are crucial for three reasons: Firstly because they limit the use of costly lightweight materials, secondly because they are the benchmark for how hard the tires will be punished. And thirdly because weight limits are what the rule-makers are likely to adjust, if it becomes necessary (as I believe it will) to slow down the die-hard V-four two-strokes to give the new breed of four-strokes a fighting chance. Just you weight and see.

Honda's adventurous move is also crucial, because it sets the pace for innovation, as well as lending credibility to ever-increasing rumors of other racing engine manufacturers who are interested in the new formula. (Renault is the latest F1 name to be added to those of Cosworth and Sauber, while MuZ and SwissAuto are two more outsiders to join the established racing manufacturers from Japan and Italy.)

There is one other important conclusion. Four-stroke GP bikes have frequently been the prototypes for future production machines, at least for the Japanese manufacturers. When Honda and the others arrived in the ‘60s, four-cylinder overhead camshaft engines were reserved for factory MV Agusta riders like Giacomo Agostini. Barely 10 years later, the Japanese had put four-cylinder sports bikes on ever street corner. It might take even less time to put a V-five in your future.

With less than a year to go, the technical rules haven't actually been finalized. Nor has a name for the new top GP class, with its mixed-capacity format for two- and four-strokes. It would be silly to call it the 500cc class, with 990cc bikes taking part. Which makes little sense of Dorna's attempt to get the whole bang shoot - 250s and 125s as well - labeled GP500. That was dropped last year in favor of MotoGP (pronounce it as one word -Motogup - and you'll see why I don't fancy it much). But that's the whole series. The senior class is sort of tentatively titled GP1 (another name tried out a few years ago), but that may still change.

Here's a suggestion. Once the four-strokes come in, why not just rename the class Superbikes?