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/127719
Max Biaggi's World Champion Aprilia RS250V (Left) Force fed by a ram-air system, the bored-out, flat-slide DeU'Orlo carburetors deliver a high volume of air and fuel to the rotary-valve powerplant. This 250cc V-twin produces more than 95 horsepower. That's right: ninety-five. (Above) Not much of a place to hide, but big enough for Blaggl. The very short and low clip-ons help to keep too much of the rider from protruding outside the smaU silhouette of the fairing• . (Below) While the carbon-fiber swingarm weighs the same as the aUoy one it replaced, it is 12-percent stiffer and offers better feel. Helping to maintain wheel control is a White Power semlactive shock. . helping exp lai n th e speed differential betw een his bike and those of his French teamm at es - the lanky Bayl e a n d "elbows" Ruggia. Bu t that's only a partial explana tio n: th er e' s no d oubt Max got the best engi ne se tu p after the firs t coup le of races, as the factory concentrated on takin g him to the title, while the fact that he used slightly narrower-secti on tir es th an th e Fre nc h 'rid e rs also helped maximize stra ight- line speed. Bu t to be cloc ked at 172 m ph on a 250, as Max was at Hockenheim, is just amazing ' - Witteveen' s mid season engine mod s conce ntra ted on wringing mor e p ow er fro m the engi ne by u s ing d ifferent exha us ts, an altere d cu rve for the openin g of th e ro ta ry va lves, an d revised combustion cha m ber shape, but the ' chassis wasn' t neglected either. Cocco's basic design was unchan ged from 1993, but WP had w orked hard on suspension . im proveme n ts, an d at th e en d of the year Aprilia d ebuted th e carbon-fi ber swi ngarm on Biaggi's bike th at was fitted whe n I rode it, and which he used for th e fin al tw o GPs . Th ere a re tw o types: one li ghter th an th e a lloy sw ingarm used before, but offeri ng the same stiffness, and the one fitted , which · is 12-percen t stiffer th an the alloy one but weighs the same. Max op ted for this one because it tra ns mits better feel, in turn p erm it ting h im to run a softer spring offe ri ng better gr ip . H ow ever, everythi ng 'S rela tive, becau se the firs t thing yo u no tice riding his bike is how stiff the sus pension setup is, especia lly at the front, but also at the rear, wh ere as in '93 WP's semi -active rear shock is used, with an elect ric motor mounted on the top of th e shock to va ry th e se tt ings accord ing to data from two sensors, one attach ed to th e th rottle linkage "at th e twistgr ip wh ich stiffens the compress ion under acceleration, the other on the front bra ke which softens the rebound d am ping under h ard bra king, so the re ar wh eel rides out any bumps more easily and retains conta ct with the gro un d. On a bumpy track like Vallelunga this seeme d to work very well on the throttle, without rear wheel cha tter or bounce when you get on the gas ou t of the pair of chicanes, but the bike was a real handful und er th e m as si ve b r akin g force d eli ver ed by th e t win Brembo carbon discs. I' ve ridden and raced eno ugh bikes fitted with "black" bra kes not to be fazed by th eir phenomenal sto p p ing p ower; and the way the Brembos worked with just light lever pr essure to bum off a little extra speed in turns showed that they are n ow b ett er th an metal bra k es in all ci rc u m stances - you don't have to worry about keeping the d isc temperature u p to opera ti ng m o d e as much as before, not even on a cool December day, thanks to the shrouds. But braking hard for the Vallelunga ch icanes 'almost every lap meant the back w heel of th e Aprilia started waving in the breeze, even with m y ex tra weig ht on board co m pa red t o Max's, a nd th e b ik e frank ly didn't feel as stable as it oug ht to under h e a vy b ra k in g - th e Honda is definitely better . It' s hard to describe wha t h appens - it fee ls as if the bike is pivoting on .th e s tee ri ng h e ad , eve n w ith qu ite a lot of steering damp er, an d of cou rse the stiff forks, wh ich are a keyfactor in allowi ng Max to sit it out on the br akes with Loris ' n' Dori an o, don 't help this adverse weight transfer. .Apart from this, the chassis handled brilliantly, steering so eas ily in to turns pratically on au topilot: you just need to . think abou t cha nging d ir ection and it does it, which wit h the steeply d ropped . ba rs an d close-coupled feel th at Max opts for (ano ther factor in hi s s traigh t line speed) is just as well: yo u don 't have - or need - a lot of leverage on the bars it steers jus t abo u t as nimbly as a 125, only it's a lot faster. The 21-degree head ang le of the forks, and very little trail are the key factors here, bu t not at the cost of ins tability - the ApriIia is really stable on fast tu rns, like the one into the stadiu m at Vallelunga. ApriIia's 250 wo rld cha m p ionshi p an d their secon d 125 crown - a re just rewa rd for th ou sands of man hours of patient development and the dedicated en th us ias m of everyone in th e Aprilia team , from Ivan o Beggio right on d own. Wh ether Ho nd a - or Yamaha - will be able to regain the world title next season is a moot point: Apri lia is now on a roll and firm ly in the technical d riving sea t. Jud gin g b y m y ri de on Magic Max' s megam ot orcycle, the Japa nese factories have a lot of work to do before next season to bridge the gap with their Italian rivals. Is that a switch ~ or what?! r c:N Aprilia RS250V Specifications ......."'...-'' "". Water-cooled 9O-degree V-twin rotary-valve tWo-stroke with twin counterrotating crankshafts and electronic guillotine power valve Dimensions .•.... .. .. .. .54x 54.5mm Capacity 249 cc Output Over 95bhp at 12,800 rpm (atgearlJox) Compression ratio 17.5:1 Cartluretion (2) 39.5 mm Dell'Orto f1at-slide (without powerjet) ignition Nippondenso digital COl with dry-celll2v battery Gearbox 6-speed extractable with integral speed shifter Clutch , . .Multiplate dry (5lriclionl6 steel) Chassis Fabricated aluminum twin-spar • Engine Suspension Front .... . . . .. . . .. .• .4Omm WP inverted telescopic forks Rear CarlJon-liber swingann with APS rising-rate linkage and single WP shock with semi·active compression/rebound damping Head angle 21 degrees (rangeof adjustment 18-24 degrees) Trail 76mm Wheelbaee 134Omm Weight ... . .•. · 204 pounds with oiVwater, without fuel tank Weight distribution fir . . .•.53/47% Brakes Front Rear 2 x273mm Brembo carbon discs with four-piston Brembo caRpers 184mm Brembo steel disc with two-piston Brembo caliper WheeIsItlres Front 3.1014.80-17 Dunlop radial on3.75-in. Marchesini wheel Rear .... .. . .. ...•...160155-17 Dunlop radial on 5.50-in. MarT:hesini wheel Topspeed 172mph (Hockenheim) • Year of construction 1994 Owner .Apnlia SpA, NoaJe (VE), Italy