Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/126997
~ ~ 00 00 O"l 1""""4 ~ ~ >I-t ~ ;j ' :::: ...... :. ~ ~ lI<,,~ # , , The Rotax powerplant featu red a new computerized digital igniti on in 1987 which enabled the team to select the ideal advance curve. The Aprilia's aircraft alloy, twin-spar chassis is extremely low-slung and the bike as a package is very little, and low. next short straight to the next second gear right-hander, saving two gear changes but still keeping the bike in the power band. The clean, precise gear-change makes use of .it a positive delight, but actually getting my foot in position to operate it was not always easy, for exac tly the same reason I encountered when I rode the original AFI Aprilia 250 at the end of the 1985 season. Like that bike, the '87 model's Carpental aircraft alloy twin-spar chassis, designed by Ga etano Cocco, is extremely low-slung. Frankly, it was a problem deciding wh ere to put my legs, and I shall have to apply to Mr. Kush itani for a new set of kneepads and a pair of boots, because there was no way to avoid dragging them in the corn ers on the little, low bik e. Of course, not only does the low center of gravity thereby achieved make the bike far easier to flick from side-to-side in a tricky chicane like the one at Calafat, but it also gives a redu ced frontal area that is one reason for the Aprilia's remarkable turn. of speed. At 155, mph this is only 2.5 mph less than the NSR250 Honda - but still, it 'is slow er - but more to th e point, it 's actually 1.2 mph faster than the 1986 World Champion machine, th e YZR250 Yamaha V-twin. Add in the ingredients of Reggiani 's riding and the Rotax's flexibility, and you begin to understand how Loris was a major thorn in the side of both Japanese teams all season long. "The Hondas are faster on top speed and accelerate better in second and third gear corners," Reggiani , says , ." b u t I can outbrake them almost anywhere and get on the gas . sooner because the power curve on my bike is more usable. On the other hand, I have a top speed advantage over the V"amahas, can out-accelerate them in midrange, and stay with them O Ul of a corner. But the Yamaha chassis handles even better than the Aprilia which I can 't really understand; look at Garriga's or Wimmer's bike, for example, and it's far taller . than either the Honda or my machine - more like our '86 bike which was much higher too , but handled really badly. But the Yamaha definitely wa s th e besthandling bike in th e 250 GPs this season, whereas the Honda was the fastest and most pow erful, while mine was the best all-around bik e. Our only real problem is reliability: small things went wrong or broke, like the ignition pi ckup at Monza which cost me a second place for sure. It co mes down to development tim e and testing; probably they're already breaking things now on th e '88 works Honda which we won 't find out to be a problem on our bike till after we've started th e GP season! That's the difference between a little team like ours and a giant like Honda." . Because it 's so low, . the Aprilia feels more like a 125cc twin to sit on than a 250, and at 1350mm , the wheelbase is very co mpact, if not ultra-short. The steering head angle can be adjusted incrementially from 22- to 25 degrees depending on the circuit, by means of eccen tric inserts: for Calafat's tight turns, it was set at 23.5 degrees, giving light but positive steering, with no trace of nervousness as on, for example, a JJCob as. Talking of which, though the Aprilia is very low and cramped for someone of my height, it is nevertheless very comfortable to ride hard, " because you sit in it rather than perched on top as on so many modern GP bikes of which the Cobas is the best example, resulting in undue weight being thrown on your The 1 9 87 Aprilia weighs in at 209 pounds dry and uses 17-inch Tecnomag nesio wheels fitted with Michelin radials; the bike is a winner. arms, wrists and shoulders which is very tiring and affects concentration. Even so, the Aprilia's forward weight bias is the same as the Cobas at 55/ 45%, proving that it's possible to attain this without making the bike uncomfortable: sorry, Antonio! Having said that, I was surprised to learn the '87 Aprilia's dry weight: 209 pounds with oil and water but no fuel - an increase of eight pounds compared Io the very similar 1985 model, but inevitable with the strong swingarm fitted, 17-inch Tecnomagnesio wh eels instead of 16-inch before, an extra pound added with the extractable .gearbox, plus the same amount with the 41. 7mm Marzocchi front forks fitted instead of the 40mm Kayabas used before, cast iron front discs instead of alloy ones which kept cracking due to heat buildup, and so on. Okay, point taken - but the bike still weighs more than I expected, even if I have no suggestions as to how they can save weight economically! Speaking of brakes, I can now appreciate how Loris can come tearing up the inside of the pack of Hondas at somewhere like the Variante Ascari at Monza, back wheel wav ing around as he stands the bike on its nose, and cheekily nips past ยท four rivals in one go including Toni Mang who is normally the last of . the late brakers, and get away with it. If there 's one aspect of the Aprilia's handling which I'd really focus on, it's those twin 280mm Brembo discs and their four-piston The six-speed gearbox is precise and clean; a pleasure to use. cali pers. Loris has the brake lever set up the way I like it, so that thepads bite very early in its travel, and after a few laps at Calafat I found myself able to throw out the anchors far better than I could ever have dreamed possible for the hairpin at the end of the straight, or the left-hander starting the sequence of second gear corners behind the pits. When you do that, there's .a noticeable but not unacceptable degree of front end dive on the MIR Marzocchi forks , which have no antidive, only rebound adjustment in the rig leg only. But they do have two-rate springs, a 0.5 kg. initial rate changing to a 1.0 kg. rate in the second half of its travel, which permits you to brake as hard as you dare, knowing that the spring will slow down the rate of dive, and the suspension will keep working. It did.