Classic duel: Flicking the Vees
Aprilia’s RS250 and Honda’s NSR250 brought grand prix style aggression to the street in the mid-Nineties, combining feisty two-stroke V-twin engines with light, sweet-handling chassis and heaps of racetrack cred
The years from 1994 saw fierce 250cc battles between fast-growing Aprilia and mighty Honda. On the track, Max Biaggi won a hat-trick of world championships for the Italian firm, before switching to the Japanese factory and taking a fourth title in 1997. And the two manufacturers’ rivalry was replicated on the street, as Aprilia’s production RS250 was launched in 1995, and came up against a similarly single-minded V-twin stroker in Honda’s NSR250.
This was the era that saw Aprilia’s rise to prominence, as the dynamic young firm from Noale in north-eastern Italy followed up its 125cc racing success by moving into the more prestigious 250cc class (equivalent to today’s Moto2). Biaggi’s works bike was a gem, holding its V-twin engine in a lightweight, aluminium beam-framed chassis. The RS250 replica’s similar frame held an engine made not by Aprilia but by Suzuki – borrowed from the Japanese firm’s RGV250.
By contrast the NSR250R, the original version of which had been created for the Japanese home market back in 1987, was all Honda’s own work. The latest model, designated MC28, combined a similar format of V-twin engine and beefy twin-spar aluminium frame. And the NSR featured a unique smart-card ignition system, allowing different power maps – radical stuff more than 25 years ago.
Super-trick strokers
The RS was no slouch in the fancy electronics department either; its dashboard incorporated the mid-Nineties novelty of a lap-timer. Aprilia claimed the RS was the closest anyone could get to a grand prix racebike on the road. It certainly looked the part in its bright orange, silver and blue colour scheme, a copy of that worn by the RSV400 that Loris Reggiani had been racing in 500cc GPs, rather than the cigarette-packet black of Biaggi’s Chesterfield-sponsored 250.
The roadster looked lean and classy from its twin-headlamp nose section to its racily angled rear end, which resembled a self-supporting carbon-fibre structure but was actually plastic, with a conventional subframe. The twin ‘carbon’ silencers were carbonwrapped aluminium rather than the real thing too, and the Aprilia’s graphics were simple stickers with no lacquer. But if that seemed a bit cheap, the finish and detailing were otherwise good, from the lap-timer to the seat hump, the top of which could be replaced with a pillion pad.
Honda’s contender was a racy and neat-looking bike too, the NSR250R SE model featuring a red/white/blue colour scheme with a green-for-250cc number plate area (remember them?) on the seat unit. The NSR was actually available in race-replica fag-packet colours – the Rothmans white/blue/gold of Luca Cadalora’s 1991 and 92 title-winning bikes – but only in the upmarket SP version, which came with magnesium wheels and uprated suspension.
In fact, even the SE model wasn’t officially available in the UK in 1995, as the NSR was a Japan-only model – albeit one that was sold in Britain and some other markets, in the days when ‘grey imports’ were big business. The normal drawback was that these Japanese market models were subject to a 39bhp restriction. In the case of the smart-card NSR, fitting Honda’s ‘tune-up’ card almost doubled the output to 70bhp. But this was designed to be used in conjunction with expansion chambers and a new wiring harness, and there was no simple street-legal way to boost the NSR.
Playing the road card
The card itself contained no battery and had been designed to be impervious to dirt, magnetic fields and even an accidental spin in a washing machine. What it did contain (as well as a small conventional key that slotted into one corner, and opened the petrol cap, helmet lock and seat-hump storage area) was a unique
serial number. This was verified by the bike’s PGM-IV computer when the card was inserted, at which point the steering lock released.
The NSR’s was no ordinary steering lock, as it was located inside the steering head stem and was much stronger than a conventional design. But it was the system’s other feature that counted on the road: the Honda’s computer read throttle position, revs, road speed, gearbox ratio and clutch position. It adjusted ignition timing, oil-pump delivery, carburation and exhaust valve position to match the map specified by the card. This was grand prix technology for the street.
By contrast, the RS250’s engine was stamped with Aprilia’s logo although the basis of the powerplant was the 90-degree V-twin from Suzuki’s RGV250. Close collaboration between the two factories had resulted in a number of Aprilia-inspired technical developments being incorporated into motors that were built by Suzuki, then shipped to Italy to be bolted into the RS.
New parts included the cylinder heads, which had a revised combustion chamber shape, plus largerdiameter coolant passages for improved temperature control. Cylinder barrels remained standard, although Aprilia insisted on stricter tolerances. The bottom-end was essentially unchanged, but the ignition system was altered slightly, and the airbox and exhaust were new. According to Aprilia the larger-volume exhaust accounted for most of the performance improvement, which was substantial: 9bhp at around 9000rpm, and 5bhp at the top end, giving a maximum of 70bhp at 11,500rpm.
Alloy-framed elegance
The compact powerplant is almost lost within the massive embrace of the RS’s frame, whose elegantly curved main spars were made from an alloy of aluminium and magnesium. The basic frame layout echoed that of Biaggi’s racebike, though the RS used cast, rather than billet, alloy at the steering head and swing-arm pivots. The roadster’s steering geometry was considerably less radical, too.
Front forks were 40mm upside-down units, made by Marzocchi to Aprilia’s specification. The front end was adjustable for preload, via a screw on the top of the left leg, and for rebound damping via a knob on the right leg. Rear suspension was by a multiadjustable Boge shock. The 17-inch wheels held a typical big-bike braking blend of 298mm discs and four-piston Brembo callipers.
The Honda, too, had a suitably racy chassis based on an aluminium twin-spar frame and Pro-Arm swingarm. Both were hugely rigid for a bike that weighed just 138kg dry, especially given the motor’s restricted output. Steering geometry was slightly steeper than the Aprilia’s with just 23 degrees of rake and 85mm of trail.
Suspension comprised 40mm forks, adjustable for preload and rebound damping (only the SP had full adjustability), and a multi-adjustable shock featuring a remote reservoir tucked inside the right fairing lower. The NSR, too, had 17-inch wheels, along with four-pot Nissin callipers biting 290mm discs.
Road and track thrills
For a mere 250 that weighed just 141kg dry (officially 3kg more than the NSR) the RS was physically quite large. Its riding position was aggressive, with a fair reach forward from the low seat to the clip-ons.
There was no electric starter, but the Aprilia required only a light kick before coming to life with a two-stroke rattle.
Its straight-line performance was certainly sufficient to grab its rider’s attention, whether on the street or on a racetrack such as Misano in Italy, where the RS launch took place. Low-rev response was pretty lazy, but carburation was clean virtually all through the rev range, it’s just that there was very little power to speak of below 8000rpm. The Aprilia was certainly no bike for effortless top-gear overtaking on the road.
Provided the revs were kept up, of course, it was a very different story. The RS came alive at 9000rpm, surging forward smoothly with a banzai shriek, and provided the tacho needle didn’t drop below that figure the Aprilia was superbly quick and exciting. If I got my line just right through the old Misano circuit’s long left-hand curve, and snicked into top just before the next flat-out kink, the little bike would indicate almost 125mph on the back straight before I had to hit the brakes, close to its top speed of about 130mph.
However, dropping below the magical nine-grand figure coming out of a bend, meant an age-long delay that would inevitably be recorded by the ever-vigilant on-board timer. Keeping the motor boiling was not easy either, despite the competent six-speed gearbox. Sometimes, in my enthusiasm for revs, I exited a left-hand bend while desperately trying to get my boot under the gearlever to change up, as the engine ran into a brick wall at the 12,000rpm redline.
Inevitably, the less powerful NSR couldn’t match those rev-happy thrills, but its engine had an appeal of its own and was far from dull. After firing up, it sounded almost like a genuine GP bike, as I pulled in the clutch lever to set the dry clutch rattling uncharacteristically loudly above the noise of the 90-degree two-stroke’s twin exhausts.
Once underway it didn’t take long to confirm that this restricted Honda had little of the Aprilia’s high-revving power and speed. What it did have was a generous spread of midrange power and torque, which made riding in town or on the open road more pleasant, if less exciting. From a standstill the NSR accelerated away easily with no need for frantic throttle-blipping and clutch slipping. There was a momentary hesitation at about 4000rpm, but almost immediately the bike was through that and into its respectably strong midrange zone.
Real power started at about seven grand, which was good because it meant there was worthwhile acceleration available from about 70mph even in top gear. On the flat the Honda had no problem holding a steady 90mph, which even made it bearable on a motorway – though its aggressive riding position and thinly padded seat (the ‘pillion seat’ was just a thin rubber patch on the tail) soon brought the normal race-replica aches.
The flip-side of the little V-twin’s impressive midrange performance was that the traditional two-stroke kick into high-rev hyperdrive approaching the 12,000rpm redline just didn’t happen. While the peakier and more demanding RS would just have been getting its second wind at 9000rpm, the NSR was beginning to run out of breath. The Honda ripped through the ton mark quickly, but refused to go all that much faster, however far beneath the petrol tank paint I crawled.
Corner-carving couple
At least the Honda’s handling was as sharp as you’d expect of a model that, in its various guises, had long been the class leader in Japan. Despite its super-steep steering geometry, the little NSR felt brilliantly stable as well as agile, and barely twitched at the bars even when ridden hard through some bumpy corners.
Much of that was due to its excellent suspension, particularly the forks, which gave a reasonably supple ride along with very precise control. The rear shock coped well too, despite my heavier-than-average body. Occasionally the back end kicked back slightly over bumps, and could doubtless have been improved still further given some fine-tuning, had not a rear-wheel puncture brought the test to a slightly early halt.
Before that, the exceptionally sticky 17-inch Dunlop radials had gripped nonchalantly even at pretty serious angles, and those Nissin callipers had stopped the little bike with a fearsome combination of bite and feel. So sound was the Honda’s chassis that it screamed out to be pushed harder on a racetrack, preferably with an extra 25bhp to make life more interesting.
Its Aprilia rival relished such treatment, thanks to a frame and curved swing-arm that were very much up to the job. Its steering response was very good, the RS turning easily without any twitchiness from its front end. Even when used hard at Misano on the launch, with the superbly powerful and fade-free Brembo brakes standing the Aprilia on its nose, the front end remained well-controlled.
At Misano the Aprilia’s rear end was less impressive, because its 150-section Pirelli Dragon radial wore very quickly, perhaps because the shock was set up too firmly, resulting in a few slides and a distinct lack of drive out of corners. But that wasn’t an issue on the road, where the Aprilia handled and gripped superbly. On the street its inflexible engine was its only serious drawback – as well as part of its charm, for this was a bike that had to be ridden hard to be appreciated.
Performance potential
By comparison the NSR felt refined but inevitably lacking in outright performance, so didn’t quite live up to the promise of its race-derived looks and technology. That was where an alternative ‘tune-up’ smart-card could have come in, but for obvious political and legal reasons Honda couldn’t let the otherwise standard roadster blow a big hole in Japan’s 250cc horsepower limit.
Even so, back in the mid-Nineties there was much speculation that smart-card ignitions would soon be introduced on other models. That didn’t happen, but the change from carburettors to fuel-injection did eventually allow the introduction of many bikes offering multiple riding modes, available at the simple press of a button on the handlebar, rather than requiring a change of card.
So the NSR250R wasn’t quite the high-tech pioneer that in some respects it seemed at the time, even though the emissions issues facing two-stroke engines were obvious back then. It was still one highly desirable race-replica though, its trickness and exclusivity going a long way to justifying the high price required to buy a low-mileage example like this one.
For most riders though, the RS250 made more sense, not least because it was available brand-new from
Aprilia dealers for a competitive price (£5495). Sure, it was demanding, and a pain in town or on a motorway. But it went as well as it looked, had lashings of GP credibility, and on the right road offered as much fun as anything on two wheels.