Honda NR 750

Honda NR 750
Jahn

Honda NR 750

Fire-red rarity

As pompous as the Honda NR 750 entered the stage in 1991, it quickly and unnoticed gathered dust in the showcases of well-heeled motorcycle freaks. Reason enough to set the rare high-tech monument in motion again.

An estimated 15 copies of the Honda NR 750 should still exist in Germany. Appreciated because even die-hard lovers and connoisseurs of the noble diva cannot give reliable figures, let alone official approvals. Because approved, just as any motorcycle is approved, you will hardly find the fire-red total work of art. With a red number for the annual and one-time drive, it is more likely. A fact that makes the search for the NR 750, factory abbreviation RC 40, a pure game of chance. If everything is set to red, Fortuna plays the address of Mr. Hettinger into the hands of the editors via a number of coincidences and contacts. A foolish motorcycle freak who not only hides his collection of rare models and brands under a fine cloth, but also regularly cruises through the Spessart and Black Forest. Because for the friendly Mr. Hettinger every motorcycle is first and foremost a vehicle and not a stationary vehicle, he refurbishes his NR 750 with a fresh battery and a fine polishing cloth for the MOTORRAD appointment. So on this way: thank you very much.

Of course, as a veteran editor, you could boil up the impressions of the test drives from 1991 again, wrap them up in fine words and rave about making the walls shake. But that doesn’t do justice to the matter and especially the Honda NR 750. For the simple reason that this stroke of genius already combined all the technological highlights 15 years ago that are celebrated today as great pioneering work: freely programmable injection, cassette gear, titanium connecting rods, anti-hopping clutch, carbon fiber cladding, digital instruments with reflex display and above all: four oval pistons. An invention in engine construction that comes pretty close to squaring the circle and with which Honda had two things in mind: On the one hand, it wanted to undo the racing classes that were limited to four cylinders. On the other hand, prove to the world that the Japanese ingenuity cannot be stopped.

There is more to the oval piston trick than the pure vanity of Japanese engineers. Namely more power thanks to less internal friction with a comparable displacement and significantly better flow conditions at the total of eight (!) Valves per »cylinder«. The disadvantage: enormously complex production with a corresponding price calculation? Piston ring 400 euros each, a piston 860 euros, 4200 euros for one of four cylinders. If a cylinder head is due during the general overhaul, grandma comes first with the piano to the pawn shop: one in four costs 8,800 euros. Even the engine specialists of a renowned Swabian piston company shook their heads with a smug smile at the end of the 1980s: »Oval piston engine? And also with power and stability? Pah, an aerial number from the Far East, nothing else. «The design of the one-piece piston rings, which have to carry and seal evenly over the round and straight area, made the CAD computers glow and the designers to the edge of madness. To be on the safe side, a shot of special lubricant is added to every NR engine when the oil is changed, which not only lubricates, but above all seals.

Tried and tested yesterday, today’s high-tech


Jahn

The technical highlights of the NR 750 were already considered a stroke of genius 15 years ago.

And yet, the oval piston engine from Honda achieved astonishing success in endurance racing and showed sensational properties at the premiere in the commercially available NR 750, albeit limited to 300 units. Brilliant speeds of up to 16,000 rpm and 125 hp in road trim, which can be increased to over 160 horses by simply switching to an HRC ignition box. In addition, a broad, fat power band that created the drivability that is much touted today. It is incredible how smooth the ultra-short-stroke V-4 engine comes from then and now. And how he brings tears of joy to the eyes of every technology freak with the outrageously throaty, robust sound of his asymmetrical firing order. In addition, the engine runs, which means that no ticking, no rattling or chirping can be heard even with pricked ears. Zero tolerances, zero rattle, just the gentle whirring of the gear cascades, overlaid by the explosive element of combustion. And only this releases delicate vibrations, which dissolve into nothing as the speed increases.

Like a turbine, the NR engine cheers through the rev range, pushing the 223 kilogram Honda forward, which, as if firmly cemented and immovable, smooths every furrowed asphalt with ease. Wild wheelies or smacking the handlebars: Nothing, the NR is calm itself. In addition, the Honda embeds its rider in comfortable seating with a finely contoured tank and flattering upholstery. In the triangle of notches, seat and handlebar stub, the human system merges with the machine system to form a painless symbiosis. The NR 750 offers more gentle comfort than agile cornering. Whereby, despite the highly controversial 16-inch front wheel, astonishingly neutral lean angles with good handling come together in a solid, if not intoxicating, bend. If you dare. Which reminds us of the definition given by the project manager responsible for the oval piston Honda in 1991: “Dynamics and elegance, no racing.” In view of the prices and the outfit, which is covered with fluorescent multi-layer paint, an illuminating philosophy.

Roughly calculated, 12,000 euros are due if you put the Nobel plane with an all-round dent in the carbon fiber parts in the gravel bed. The bluish shimmering, titanium-coated windshield alone is in the catalog for 1400 euros. The instrument cocktail below goes over the counter for 2500 euros at a real bargain price. Exclusivity has its price, but it ensures full employment. Because with customer service, the mechanic bills 24 hours, i.e. three working days. One of the reasons why, after a few kilometers of test drive, we lift Mr. Hettinger’s NR 750 unharmed onto the red assembly stand. Off to the showcase, earn money. If you prefer to invest your home loan and savings contract in a Honda NR 750 rather than your own home, you should get it now. The rare Hondas are traded for around 35,000 euros. At an official new price of 100,000 marks, or 51,129 euros, this is an opportunity. And the fire-red NR 750 is not everything. A workshop manual with all the details and technology secrets in German is included as a bonus. As thick as the Tokyo phone book and more exciting than any crime thriller.

Data Honda NR 750 (RC 40)


Jahn

As long as there are NR fans, this Honda diva will not lose her place on the stage.

Engine:
90-degree V-4 four-stroke engine, oval piston 101.2 x 50.6 mm (corresponds to a bore of 75.3 mm), stroke 42 mm, two titanium connecting rods, eight valves per cylinder (20 and 18 mm diameter), Freely programmable injection / ignition, anti-hopping clutch, six-speed cassette transmission.

Landing gear:
Aluminum bridge frame, USD 45 fork at the front, single-sided swing arm at the rear, double disc brake at the front, 0 310 mm, single-disc brake at the rear, 0 220 mm, tires f / h 130/70 ZR 16, 180/55 ZR 17.

Mass and weight:
Wheelbase 1433 mm, steering head angle 56.5 degrees, weight: 223 kilograms,

Price:
100,000 DM (1991) limited to 300 models

Related articles

Leave a Reply

Your email address will not be published. Required fields are marked *