Cycle News - Archive Issues - 1990's

i1eged so li tary rider for whom this unique comparison test was organized, it was both a happy day, and a sad one: after the fairy-tale endeavors of the Ca tiglioni brothers for the past decade and a half from close up, and sampling each year's 500 Cagiva vintage in succession, it was the end of the line for one of the rno t quixotic tories in modem GP history - the last time the 500cc Cagivas would run on a race track. One of the problems with EFI is that preparati9n for actually running the bike is quite time-consuming: Before it could be fired up, development engineer Andrea Goggi had to program in the software he had previously prepared, in the form of two supplementary optional maps for the EFl, in addition to the base map incorporated in the .TAG ECU. The rider then selects each of these three in turn on successive shakedown laps, by means of a three-way switch on the left clip-on, allowing the team to download the data from their acquisition system after he's returned to the pits and to analyze it before choosing one of the maps or perhaps modifying it until they achieve an optimum setup. 1 have to admit I couldn't tell the difference between any of them actually riding the bike, but Goggi says that is normal. "The system is only there to facilitate setting up the bike ideally in qualifying . or pre-race warmup," he says. "It saves having to change the EPROM chip to fine-tune the bike like you have to do on the Ducati system, for example." So while Andrea concentrated on plugging in the programs via his portable mainframe computer to the onbike TAG ECU mounted on the right (Left) The fuelinjection control unit Is mounted to the right frame spar. Three maps are contained in memory at one time, the rider able to select each with a three-position switch on the left clip-on (below). tal-alloy composite chassis, with the different sections glued and riveted together aircraft-style to deliver a twin-spar frame offering a 10-15 percent improvement in the stiffness-to-weight ratio compared' to an all-alloy one - less than the 20-25 percent improvement offered by an all-carbon chassis, but with the added advantage that alterations to the steering head or swingarm pivot design can be carried out far more quickly. Cagiva ran into this over-stiffness problem back in 1990 when they had Ferrari build them an all-carbon chassis, which yielded extra difficulty in terms of causing the crankcases to crack, because carbon doesn't filter out the vibrations as well as alloy. The composite frame is a good compromise, and proved its worth when, in an attempt to cure an under(Left) A big electronic tach highlights the cockpit. Po_r comnon strong at 9500 rpm with peak output at 12,600. Throttle response on the Injected bike was better. frame spar, I went out to set my own personal baseline by riding the carbureted bike. This was one of Kocinski's two '94 bikes, modified for Chili to ride by reverting to Chandler's suspension settings because the Italian's weight is similar to his. The steering geometry, on the other hand, is closer to Kocinski's, who, like Chili, rides the bike as though it were a 250, with high cornering speeds dictating a less-radical setup aimed at holding the line in a turn. Chandler prefers a quicker-steering, less-stable bike to suit his dirt-track-derived Roberts-replica riding style. ew for '94 was chassis designer Romano Albesiano's beautiful carbon-fiber I Carpen- steer problem midway through last season, Kocinski wanted the engine moved in the chassis to put more weight on the front wheel. The result is the best-steering 500cc GP bike I have ever tested, a bike which changes direction so quickly and easily in the Mugello chicanes I half thought I was riding a nimbler 250 - well, until I came to pull the trigger on that massively powerful V-4 engine, that is. You notice the agility most in the tightest chicane of·the three, at the top of the hill, where you actually have to come back on yourself on the exit to get a good drive out along the short straight down to the next right-hander. Not only did the Cagiva steer through both parts of the chicane with remarkably little effort, I could pull it upri~t quite early on the way out to get a hard drive on the fat part of the tire. It's a bike th.at wants to do what you tell it, rather than insisting on being muscled around to do things against its will. Yet this hasn't been obtained at the expense of stability. Both Cagivas - the injection bike had the same geometry, only a di.fferent suspension setup for Fogarty's Donington ride which wasn't as good over bumps as Chili's for Mugello - held the line I would pick for them down the fast offcamber sweeper behind the pits really well. If any turn will make the front wheel wash out, it's this one - and it didn't happen, either there or on the crucial last sweeper before the pits, which determines how much speed you'll get on th.e main straight. Great steering, good handling, excellent chassis. And considering that Albesiano has designed the twin-spar alloy frame for the Cagiva F4 Superbike, it'll be interesting to see how much of this excellence can be transferred to the four-stroke racer I roadster: quite a bit, I suspect... One feature they won't be transferring is the Brembo carbon brakes, running unshrouded on a hot 90-degree day and in the smaller 290mm diameter favored by Chandler, rather than the massive 320mm black brakes Kocinski often used. These are now incredibly sensitive and responsive, just a light touch with.a single finger enough to brush off a little unwanted speed in a tum, while still supplying eye-popping stopping power at the end of a straight. Their light weight is surely a factor in the Cagiva's outstanding steering - but so too is the ideal cocktail of settings for head angle, offset I trail, wheelbase, engine position, swingarm pivot location, and front and rear ride heights that the Cagiva GP team has evolved. Make no mistake - when these guys appear on the World Superbike scene in 1997, they're going to bring with them a level of expertise that will raise the already high four-stroke racing stakes even higher - having spent '96 developing the F4 in U.S. Superbike racing and World Endurance events. Cagiva may have turned a page after my test day - but it's not the end of the book: far from it. Ca,giva made one other change to Kocinski's bikes for Chili to ride them they converted the engine back to their traditional 56 x 50.6 mm dimensions, rather than the "square" 54 x 54.5 mm format used by Honda and Aprilia to win all three GP world titles in 1994, and which Kocinski raced with for the first and only time at Barcelona in the lI') 0\ 0\ rl trl N l-< (IJ "£ o 23

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