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November, 9, 1991: Honda NR750 RC40 first test

Published: 06 October 2015

'HYPER! HYPER! – Honda take road bike technology to new heights with the oval piston NR750. But can it live up to all the hype?' Mat Oxley was first to ride the £38,000 gem – the RC213V-S's louche great uncle – at Circuit Paul Ricard in France.

Full of characteristically unexpected insights – did you know the suspension was done by the same guy did the Aspencade and the Pan European's? – Mat Oxley does a consummate job at not having his head overheat on what what was one of the most anticipated tests ever. 'Materials, machining, everything is of a quality never usually seen on a motor cycle'. But what's it all for?  


onda’s NR750 has become the Madonna of motor cycling, hyped to the heavens, it has come perilously close to publicity overkill.

For months, years in fact, you’ve not been able to open a motor cycle magazine without this technological marvel staring you in the face. Instead of Madonna’s putting red lips and risqué statements, there’s the voluptuous red bodywork and mind-boggling specifications. And like Madonna’s career, the NR sage has been precisely staged, carefully milked for maximum publicity. Little by little Honda have revealed their proudest achievement. First there was the 500 HP bike, then silence, then the 750 endurance racer, then silence, then the road bike’s tantalisingly brief appearance at Suzuka 1990, then the dilly-dallying, will they sell it or won’t they? Finally you get to go to the flicks and see Madonna in bed. Finally you get to read about the NR in action. There’s the danger of a massive anti-climax.

Honda knew this. The Japanese didn’t even plan a journalist riding launch – they’d prefer the bike to retain its mystique – but once on sale an NR would inevitably get into press hands. Thus the invite to Paul Ricard in the south of France for a fleeting ride. Anyone expecting a rip-roaring tool, sharpened and honed for the race track will be sorely disappointed. The NR750 racer peaked its development curve at 170bhp and, as Honda say, NR designers “dared not pursue only dynamic engine performance” for the road. If you drooled over the machine at the NEC, you should know that already. The NR is large, rounded, accommodating and soft. The styling is opulent rather than racy and the exhaust doesn’t bark aggression. Honda built their bike to boast their engineering prowess, not to break any records.

'Ignore talk of revolutionary'

The NR doesn’t shock with its speed. It’s fast, of course, it’s bloody fast, but there are quicker bikes around. And the greatest achievement of the engine is that it makes more feel less. A peak power output of 130bhp is not insignificant but the NR produces that power in the calmest, most laid-back way possible. Unless you’ve been marooned on a desert island for the last decade you will already know why. Here’s a quick re-cap anyway: With eight valves and two spark plugs per cylinder the NR offers V8-style intake and combustion efficiency with V4-style internal friction. The engine gets close to having the best of both worlds. But please ignore talk of ‘revolutionary’ – Triumph designer Colin Ridley built an oval piston motor in 1922.

A metaphor is born!

The arrangement works so well that it gives serious power and torque over a much greater range than a conventional motor. The NR’s spread is gigantic. There’s no Everest-like power curve, more a flat plateau that goes on forever like the plains of Wyoming. It reaches from 8000rpm, grows and grows to the 14,000rpm red line and barely seems to tail off before the rev limiter stops play at 16,000. Oval pistons don’t work alone though. The NR is equipped with programmed fuel injection and ignition. The injection microprocessor feeds on split-second data from seven inputs (air temperature, pressure, throttle setting etc), adjusting fuel and air flow through the eight separate throttle bodies.

Throttle response is perfection all the way through the rev range and it seems to make little difference whether you shift at 11,000, 12,000, 14,000 or 15,000rpm – power is just everywhere. Wonderful indeed but the NR doesn’t trigger your adrenal glands into flooding your veins with excitement. The 90 degree vee is dead smooth, so only the speedo (itself a victim of techno-overkill – the LCD image ‘floats’ in the space, reflected upwards by a mirror) keeps you in touch with reality. You end up climbing off the NT overwhelmed by the machine’s technical excellence. But then you ask yourself whether you had a good time and you realise you feel more numbed by its perfection than thrilled by its performance. High-speed sensory deprivation is not an uncommon factor with modern hyperbikes – the NR just takes it a little further. Maybe the experience would be better on the road, away from the artificial road track environment.

'Makes a Bimota look ordinary'

At least the world’s most expensive bike stays unflustered when reality finally catches up with its rider. The bike is not a lightweight, weighing just a few kilos less than Kawasaki’s ZZ-R1100, but the handling and steering is in a different world. Sixteen inch fronts come back into vogue with the NR. But fret not, the NR isn’t nervy like similarly-equipped bikes of old. The specially made Michelin 130/70x16 combines with conservative geometry (24 degrees of rake) to make the NR feel far lighter than its 222.5kg. Not only is the NR heavy for a 750, it’s also pretty big, so the riding position doesn’t cramp you into an aggressive crouch like race replicas. NR test riders say they spent months working on the ideal position and they’ve done a good job. You feel at home right away, hunched comfortably over the gorgeous curves, backside perched on specially formulated seat rubber, hands grasping specially-designed grips.

The suspension could almost be off a touring bike (no surprise since the NR project leader last worked on the Aspencade and Pan European) but it’s anything but the junk equipment which spoils so many Japanese sports bikes. Soft it may be but the damping control is superlative so the NR handled Ricard’s twists like a real sports bike while simultaneously shielding its rider from those infuriating F1 ripples created by Senna and Co. The NR proves just how good suspension can be when the designer isn’t shackled by a budget – materials, machining, everything is of a quality never usually seen on a motor cycle. And that goes all the way through the machine.

'Oval v-twin & tourer likely'

Chassis rigidity is beyond question. The massive (polished) beam frame is fronted by monumental 45mm upside-down forks and triple clamps machined from ultra-tough Duralumin. We are talking major stability. Honda say they’ve never designed a more aerodynamic bike and the fairing helps pin the NR to the tarmac to keep is steady at terminal velocity (about 170 at a guess). The NR illustrates (for those who ever doubted) that the Japanese can build a motor cycle which makes a Bimota look rather ordinary. It may cost almost twice as much as a Bimota and four times more than most superbikes but anyone who breathes in the quality, runs their fingers across the bodywork and feels the polished perfection of the suspension will want to know why their CBR, FZR, GSX-R or ZXR feels tacky by comparison. That could be the whole idea though. As worldwide demand continues to drop, all motor cycle production is becoming relatively limited and therefore high cost per unit. By producing the NR, Honda are re-defining the acceptable cost of motor cycling. With a £38,000 bike at the top of the range, everything else looks cheap.



The bike is a technological masterpiece but however wondrous the engineering may be, however beautiful the execution, the NR is sterile. It fails to give its rider a real buzz because it lacks that rough edge that all the most desirable bikes and cars possess. The NR’s four wheel stablemate, Honda’s Ferrari-esque £65,000 NSX, has already come in for similar comment from testers who are more used to less refined, more charismatic Ferraris and Lamborghinis. The NSX may outperform its Italian rivals in so many respects, but it fails to stimulate the driver so effectively. Either the NR lacks that crucial, unquantifiable ingredient or I’m simply incapable of enjoying myself on something which costs quite so much money. Or it’s just too perfect to be appreciated.

If you can morally justify the billions of yen spent on development, the NR does have a reason for existing beyond itself, however. Honda don’t see oval piston technology as a dead end alley. The knowledge they’ve gained over the last 15 years is filtering into a new generation of machines. An oval piston V-twin and a tourer are likely follow-ups to the NR, the tourer making sensible use of the incredible power spread. Meanwhile the motor cycling world watches and waits. Can Honda really sell around 700 NRs at £38,000 apiece? I’m sure they will. The richest two wheel fans won’t be able to resist it. But how many will you see on the road and how many will stay at home, gracing the interiors of the rich, like pieces of modern sculpture?

Specification

Price £38,000

Engine Liquid-cooled 90 degree V4 with DOHC and 32 valves, oval pistons, twin spark plugs and dual
connecting rods. Capacity: 747.7cc. Bore and stroke: 75.3mm x 42mm. Compression ratio 11:7:1.
Carburation: PGMFI fuel injection. Maximum power 130bhp at 14,000rpm. Maximum torque 50.6ftlb
(7.0kgm) at 11,500rpm. Wet sump lubrication


Transmission Primary drive by gear. Final drive by chain. Multiplate, semi-slip wet clutch.
Six speed gearbox
Electrics 12V 12AH battery. PGM computer-controlled electronic ignition. Headlight: dual halogen
high beam, projector low beam
Cycle parts Frame: Twin beam aluminium. Suspension: 45mm upside-don Showa telescopic forks
with pre-load and 12-way compression and rebound damping adjustment. Pro-Link rising rate linkage rear
with Showa nitrogen-charged shock adjustable for pre-load, compression and rebound damping.
Wheels: Cast magnesium live spoke, 3.50-16 front, 5.50-17 rear. Tyres: Michelin HI-Sport radial,
130/70ZRR 16 front, 180/55ZRR 17 rear. Brakes: Twin 310mm front discs with four piston calipers,
single 220mm rear disc with twin piston caliper
Dimensions Wheelbase 143.3cm (46.4in). Length 214cm  (84in). Width 70.8cm (27.9in).
Seat height 78.7cm (3in). Dry weight: 222.54kg (489.5lb).  Rake: 24.5 degrees. Trail: 8.7cm (3.4in).
Fuel capacity: 17.3 litres (3.8 gallons)
Warranty 12 months / unlimited mileage
Importer Honda UK, Power Road, Chiswick, London W4 5YT. Tel: 081-747-1400