Aprilia RS 250 test comparison against Honda NSR 250

Aprilia RS 250 test comparison against Honda NSR 250

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Aprilia versus Honda – Italy versus Japan. The tough Grand Prix duel of lightning-fast two-stroke engines is now available with street legal approval.

Former RD 350 drivers will confirm it: From a rational point of view, there were a number of reasons why you should swap your two-stroke engine for a solid yoghurt pot. Even in the hustle and bustle of the city, it twitches without grumbling. And for two – impeccable draft. It was terrible, this eternal turning work with the two-stroke ratchet. It’s better to have a gentle, easy-care four-stroke mule.
But sometimes you would like to do it again. Sunday mornings, between breakfast and Eurosport GP broadcast, pound the house route, squeeze out the two-stroke rattle until it comes sweet, the aisles just pecked through. Braking, flipping and around the corner with playful ease.
Fortunately, there are still a few very delicate specimens of this type of motorcycles in the shop window today. Aprilia‘s RS 250 with the Suzuki RGV-250 engine, for example. Black as night, crouched and on the side stand faster than the rest of the world, she stands there like King Max’s (Biaggi’s) throne in person. As a counterpart, the former GP driver Hans Becker (IMT, phone 02741/60453) imports the replica of Waldmann’s Honda NSR 250 designed for the Japanese market. Delicate, light and with a stylish rattling dry clutch. Both skip the strict German emission hurdles using an unregulated catalytic converter. Currently the only way to effectively detoxify the lively two-stroke engines without losing too much horsepower.
There are no compromises when it comes to having fun with the two tiny creatures. But watch out, it’s not as easy as it sounds, at least in the case of the Aprilia. If your speed and engine power do not harmonize, it is quickly done with the targeted line. So we rummage through the pool of long moped experience, break around the corner with a lot of momentum, turn the gas tap a few meters earlier than we are used to from the yoghurt cup – and then things go smoothly.
Honda’s two-stroke whisk, whose basic design is very similar to the Aprilia / Suzuki concept, impresses with reliable thrust from almost all positions. Even if the performance diagram diagnoses a few dents in the NSR engine (page 33), the Honda rushes through the tight labyrinth of curves with half switching work, promptly releasing every throttle command and leaving the Aprilia no choice but to hack after at high speed and occasional clutch magic. Which is why the short-stroke V2 engine also has to admit defeat at the gas station by the balanced NSR two-stroke engine with the proven square stroke / bore ratio of 54 x 54 millimeters.
A handicap of the Aprilia RS 250: the ridiculously large gear ratio jumps of the first three gears, which in addition only move into position with a clear "clack". The NSR can do that better, but the Honda drive hits the chain quite hard when the load changes. Yes, yes, it takes a few tank fillings to come to terms with the rough edges of the two flails.
As a reward for the patience and hard work there is not the often cited maneuverability of a bicycle, but even compared to very nimble 600 sprinters, the Honda actually only needs half the force to knock the 152 kilogram flea around to bend the corners. Despite the comfort-oriented spring elements, the brisk country road dance still has enough stability to stage lightning-fast course changes with the NSR without rocking and jerking. The only spoilsport for pleasure: the standard Dunlop "Rideen" tires. Little grip and quite sensitive on bumpy roads, the series tires are actually only good as rim protectors. That is why the GP stars and the MOTORRAD testers prefer to put Dunlop rubbers of the finest quality over the cast wheels: Sportmax D 207 in a sticky “GP” compound and of course with road approval. Soled like this, the compact – almost too compact for two-stroke freaks over 185 centimeters in height – and the short NSR 250 can no longer be disturbed by anything and is ready to overcook the Aprilia on the race track.
Well done, after all, the RS 250 has an artfully formed aluminum chassis that not only looks stable, but also drives like that. In its case, the handiness tends to move further away from the bicycle and towards the 200-kilogram yoghurt pot, but it sucks its way through country roads of all quality in a rock-solid way. The Aprilia care about bumps just as little as the wildest asphalt faults. Occasional jerks in the handlebars can be clearly seen, but are within acceptable limits with a soft country road setting.
The Metzeler ME Z 1 tires fitted as standard on the RS convey a good feeling in terms of grip, of course in a "Racing" mix. But unfortunately the 110 and 160 millimeter wide rubbers resist handiness and demand tight reins from the Aprilia jockey when turning.
Tightly and directly coordinated, the Aprilia technicians adhered to the Italian tradition of chassis construction. The spring elements convey the kind of feedback that spoiled yoghurt cup owners initially rate as uncomfortable, but after the third lap on the house route they recognize it as a highly informative dialogue with the slopes. While the Honda uses up most of its damper reserves in the country road trim, on the Aprilia the adjusting wheels on the fork and shock absorber are still on "soft". That should change.
Horse and rider have free rein on the home-and-yard race track in Hockenheim. Now the Aprilia is also wearing the Dunlop sports shoes, and both of them blow their hot sound through the Motodrom through Jolly Moto pears (see also page 30). The Honda is about to pull another joker. The roadworthy chip card, which also serves as the ignition key, is replaced by an "HRC card". The difference: a more aggressive ignition curve provides more thump when accelerating and a little more end output, but at 11,000 rpm it is time to end, while the ignition curve of the street version stays on the pusher a loosely 1000 rpm longer.
The NSR peppers through the corners as lightly as a piece of balsa wood, but because of its soft spring / damper coordination, it has a hard time converting the impressive handiness into speed. With wise foresight, the spring of the single-sided swing arm has already been replaced by a harder one. And yet the NSR lacks ground clearance and stability in the wild waves of the Baden race track. Hardly anything can be made good on the brakes, because the torsion-resistant, but also too softly tuned 41 mm telescopic fork is not quite up to the full, perfectly adjustable double disc stoppers and can be compressed to the limit in wavy passages.
The powerful pulling force of the NSR 250 engine is unfortunately followed by a sudden drop in performance with the slightest attempt to overrevise. The result: heavy switching with constant eye contact with the rev counter. Tenth for tenth fall victim to the annoying rev limiter, and so the chronometer stops at a meager 1.17.1 minutes. what a shame.
Even the Aprilia does not find the right rhythm with the standard overall gear ratio in the Motodrom, but can be mercilessly overturned when it is pressed, thus saving one of the other gear changes and also hiding the gaping gear jumps. There is only one effective way to counter the hesitant throttle response on the race track: brake, shift, immediately bring the throttle to the stop and balance in a mercilessly inclined position and with a clean line up to the crank.
Ultimately, the Aprilia secures the decisive advantage with its stable chassis with a finely adjustable shock absorber. With fully adjusted compression damping, the grip on the rear wheel continues unabated in the bumps and compression passages. Only the telescopic fork, the spring / damper functions of which are divided into a fork leg, twist noticeably when braking. The Brembo pliers are quite snappy, but with a moderate dosage and not completely fade-free. The bottom line is that the Aprilia remains the winner in the ring with 1.16.1 minutes.
F.Done, pack up, end of test. Think, because before all the reserve canisters of fuel are empty and the poor Dunlops hang in tatters from the rims, you can’t get any of the MOTORRAD testers off the slopes. And tomorrow they will tell you again the stories of wind protection and reliability and draft and reason and in general. Well, tomorrow is tomorrow and today is today.

Honda: Race track classification – 2nd place

Too bad. In and of itself, a lightning-fast, super-handy device with the best brakes and razor-sharp steering precision, which unfortunately the soft suspension set-up tailored for the Japanese market makes difficult. In addition, the powerful, balanced engine lacks the necessary maneuverability in the sports trim, and so the Honda RS 250 SE unfortunately does not quite meet the high expectations in the sports classification.

Aprilia vs Honda: Battle of Concepts

Aprilia chases Honda, Honda chases Aprilia. The same game for years when David from Italy steps into the ring against Goliath from Japan. This season the fight got a most smug upgrade. Due to the disputes in the Aprilia team, the self-centered but fast Italian Max Biaggi moved to the Japanese Honda camp. His place in the Italian Aprilia team was taken over by the Japanese curving talent Tetsuya Harada, but it is more than the ambitious competition between two motorcycle companies and their highly paid drivers, it is also the competition between two engine concepts. On the one hand there is the construction principle of the Dutch designer and chief engineer Jan Witteveen, who consistently relies on the sensitive but powerful rotary plate valve for inlet control. Its two-stroke twin, which is manufactured by Rotax in Austria, works with two crankshafts that are positioned one above the other and rotate in opposite directions and is the very strong, but also capricious, high-performance two-stroke engine. One nozzle too rich or too lean and there are problems. Years of trial work and test drives brought Aprilia the first world championship title in the 250cc class in 1994, which until then had been dominated by the Honda and Yamaha factory machines. At the beginning of the seventies, Yamaha threw the sensitive engine concept overboard and modernized the 500 and 750 TZ series with the membrane systems dubbed the sniffer valve. The advantage: The actual intake control time depends on the current vacuum conditions in the crankcase. Fresh gases that have flowed in can no longer be pressed out of the precompression chamber even when the flow is reversing. In the case of rotary vane motors, on the other hand, the control times, which are determined by the free section of the rotary valve plate, are unchanged over the entire speed range. Thanks to the combination of diaphragm inlet and electronically regulated outlet control, the increasingly powerful two-stroke engines were not only controllable for the factory drivers. The road two-stroke and motocross machines from almost all manufacturers have also been using the Yamaha model since then. Honda NSR engines have also been working successfully with these systems for years. However, they are denied the very last bit of maximum performance due to the flow resistance of the membrane plates, a disadvantage that the Aprilia factory machines impressively implement in their favor on fast GP roads. The construction principle of the roadworthy NSR 250 SE is very similar to the current racing engines but from the production racers born in 1992. The last model variants of the SE look confusingly similar to the current racing machines due to the one-armed cast swingarm and a modernized design. With full intent, because competition is raging on the Japanese market too. And what attracts more than the direct connection to the great successes in racing? In the Aprilia road machine, on the other hand, the engine model of the road machine has little in common with the complex racing engines, but is almost identical to the Honda construction principle. Water-cooled V2 motor with membrane inlet, six-stage quick-exchange gearbox that can be pulled out of the housing from the side without having to dismantle the motor. Differences in detail can be seen in the exhaust control, which is regulated on the Honda with a very efficiently working flap mechanism, while on the Suzuki exhaust two three-stage flat slides are activated by servomotors. The mechanics of the Aprilia are unfortunately very fragile and caused major damage in many engines due to a loose locking pin. Both motors are mounted in rubber elements to decouple the vibrations. In contrast, a balance shaft on the Honda racing engines has been ensuring smooth running since 1993 and thus the possibility of integrating the engine block as a rigidly screwed, load-bearing element into the bridge frame. It is questionable whether Honda will also bring its road offshoot up to the current state of racing technology in the foreseeable future, since the exhaust gas problem typical of two-stroke engines can only be mastered with difficulty with conventional technology. The only bright spot at the moment is the Bimota-Vdue project (see page 15). MOTORRAD was able to check how different the two engine concepts of the factory machines have in practice in driving tests. While the Honda NSR 250 does its work willingly and smoothly in all speed ranges, the Aprilia parallel twin gives off a rather tired and unwilling performance below 9000 rpm. This is where real racing professionals are needed who can convert the last bit of revs into power and speed. Anyone who hesitates or prefers speed-reluctance to pull through has lost. It is not for nothing that the more good-natured membrane motors usually drive ahead in the rainy races, because under such circumstances top performance means little, but controllable torque everything. That the Italians take their job in the world championship very seriously is also evident from the immense technical and financial effort of the works team. The swingarm and wheels at the factory Aprilias are made of the high-strength, lightweight, but also extremely expensive carbon fiber material. With the wheels in particular, there is a noticeable advantage due to the reduction in rotating masses, which promise better handling at high speeds and slight advantages in acceleration. Honda still shies away from the enormously high costs and relies on solid aluminum or magnesium alloys for all load-bearing chassis parts. But the efforts of the Aprilia team around race director Carlo Pernat paid off: three years in a row, the world title went to Max Biaggi and the busy factory in Noale. So what could be more obvious than to assemble the successful RS 250 racing machine for the general public. Frame design and paneling of the real factory machines, paired with the low-cost, high-volume V2 engine from the Suzuki RGV 250, and the Biaggi replica was ready. Even if it has little more in common with the GP motorcycle than its charisma, it is still the most shameless seduction of adults.

Aprilia: Classification of the racetrack – 1st place

With a high-revving engine and a stiff chassis, the Aprilia compensates for the great power development and the ridiculously wide stepped transmission. Nevertheless: Just sit on it and drive off is not possible. Only those who get involved with the Aprilia with enthusiasm and passion will find access to a high level of driving dynamics.

Honda: Road rating – Honda NSR 250 SE

The solid little engine manages the brilliant balancing act between pulling power and maximum performance. Modest in the city, lively across the country and the whole thing with acceptable consumption, the road ranking goes clearly to the Honda. Flawless equipment all round, solid workmanship and in terms of handiness can hardly be surpassed, only the series tires cannot keep up with the other qualities.

Close-to-series racing – popular sport: everyone against everyone

So now it’s in the garage, the little two-stroke racer. You undoubtedly have fun with it on the street, but the dynamism in it cannot be implemented with real pleasure. So off to the race track. Because only without oncoming traffic and framed by friendly gravel beds can you move forward properly. For example at the Aprilia Cup. As part of the Euro Cup, all participants race there on the modified RS 250. According to a set of regulations, the standard engines have around 66 hp. At the four weekend events, two races and lots of training runs take place. The best young drivers are invited to a talent test on Aprilia racing machines. The entry fee for the entire racing series is 1490 marks including team clothing, food and technical support. The weekend costs 380 marks for casual starters. Contact address: Aprilia-Cup Organization, Dortmunderstrabe 23, 41564 Kaarst, phone 0521/44 703 53. The ADAC-Cup is not that familiar. There, the ambitious German B-license youngsters meet to exchange blows on 250 two-stroke machines or 400 four-stroke machines. Of course, strict regulations slow down escalating material battles and ensure that the running costs remain within reasonable limits. For example, tire warmers and automatic switchgear are prohibited. Road sports tires, which can be fitted with a maximum width of 120 and 160 millimeters, are used. The minimum weight for two-stroke engines is 140, for four-stroke racers 165 kilograms. Maximum power of 67 hp is permitted in the ADAC Cup. After seven races per season, the cup winner has been determined who, with the right talent, can count on generous support for his future racing career. The entry fee for the entire season including several days of preparatory training is 2500 marks. Contact address: ADAC-Munich, Am Westpark 8, 81373 Munich, Attention Ms. Breitholz. From the former rally championship, the motorcycle series sport class emerged for the 1997 season. There the machines have to comply with the StVZO in the broadest sense. On permanent circuits, an endurance test and a sprint test of at least 40 kilometers with a standing start are carried out. The starting line-up is made depending on the current score. The total distance traveled is at least 201 kilometers. If you can’t get enough to drive here for your 200 Mark entry fee, it’s your own fault. For the ADAC Cup and the series championship, an OMK license is required, which can be requested from the OMK, where there is also further information on the series class. Contact address: OMK, Waidmannstrabe 47, 60596 Frankfurt. Another popular opportunity to really let the cow fly is the free training sessions for amateur racers on closed and secured racing slopes. However, as a beginner, you should stick to the training offers, which put your driver groups together in such a way that beginners with beginners and professionals with professionals on the slopes or instructors take over the briefing of the newbies. Dates and addresses: in MOTORRAD or in the classifieds section of Motorsport aktuell.

Aprilia: Road evaluation – Aprilia RS 250

City trips and short-haul traffic are not the strengths of the agile, but nervous and thirsty two-stroke engine. Even those who master the game of shifting, clutch and gas with virtuosity are challenged so as not to lose sight of the Honda. But even two-meter people can cope with the generous space of the Aprilia RS 250. Equipment and workmanship are good standard, the stable and beautiful chassis in fast corners in a class of its own.

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