Cycle News - Archive Issues - 1990's

.was given the code name 'UFO'. but the results obtained with it led directly to the crucial decision reached in November '78 to pursue the oval piston format and build a ,full-size V-4 version. Honda had bitten the bullet, The first NR500. termed the OX (as in Zero X), was duly completed in April 1978. and employed a number of then-radical features. many of which were later to become adopted by companies other than Honda. like the upside-down front forks, monocoque chassis (which however was so poorly designed that the engine had to be removed to change the carburetor jettingl), alloy construction, risingrate monoshock rear suspension, sidemounted radiators, and 16-inch wheels - the first time these were employed in the modem era since the 500cc Jawa works GP racer of 1956. But it was the ' engine that was truly revolutionary, a lOO-degree V-4 four-stroke with four oval pistons. eight conrods and spark plugs, 32 valves, twin overhead earnshahs gear-driven up the right side of the engine, flat-slide carburetors and an ultra short-stroke of (93.4x41) x 36 mm, Though subsequent development would see many changes to the design, its basic format would be retained right up to and including the development, of the NR750 roadster. ' . This first NR500 engine delivered 100 bhp in early bench tests in July 1979, eventually rising to 115 bhp at 17.500 rpm by ' Decem ber. With the complete bike buill to a very small scale - it was scarcely larger than a 250/350 TZ Yamaha of the era - and no expense spared to save weight, it scaled a respectable 275 pounds, which on paper made it very,competitive against the 122 bhp/299 pounds .. power to weight , ra tio of the works • XR27 Suzuki which ' won the Manufacturers World title that year .in the hands of Barry Sheene and. Virginio Ferrari. But reality was -d i f£er enl : .~ though it revved to over 20;000' rpm safely, the Honda was very hard to ride. with no flywheel effect so that it stalled when run under 7000 revs. This made starting it in those days of push-stan GPs an acquired skill. quite apart from the fact that the promised power was not translated to the road, and the avant-garde chassis produced no end of handling problems. not improved by the futuristic tire choice. Honda had taken several steps too many all at the same time. and ,the results were predictable. Having announced their return to GP racing back in 1977 a public statement they were undoubtedly forced into by the fact that their three Japanese rivals were all winning GP races on the tracks - Honda was under considerable pressure from all quarters, not least the European press. to live up to that commitment by finally putting in an appearance at a race meeting with their promised machine. Almost two years had gone by since company president Kawashima had made the announcement, a premature declaration which placed undue pressure on Irimajiri and his team to streamline the development of such a radical new design. Forced to race the NR500 before it was ready . Honda suffered the predictable outcome: two bikes were entered for the British GP at Silverstone in August '79. ridden by Mick Grant and Takazumi Katayama, and qualified in the last two places well off the pace. Grant's race ended at the first comer in a fiery crash which ensured maximum publicity for the embarrassing failure. and Katayama retired without ever passing anyone. A month later in the French GP at Le Mans, Honda plumbed the depths of humiliation when this time both bikes failed even to qualify. To make matters worse. the decision was made to send them both out on the warmup lap so they could start the race in the unlikely event another one or two runners expired on their way to the start line! In truth, this was a ploy by the organizers to assuage the disappointment of the large crowd who had shown up to watch the Hondas in action, but the sight of the two bikes being expelled from the grid must surely represent the nadir of Honda factory fortunes in any fonn of racing at any level. Yet from this utterly disastrous fiasco, Honda was to develop the most sophisticated. most technically advanced and most exotic street bike ever offered for sale to the public, the NR750: it is impossible not to admire this achievement, Honda's prestige was now at stake in a big way, but instead of aborting the NR project and building a fourcylinder, rotary-valve, two-stroke like everyone else. they intensified development of the NR500. Design work started in November '79 on a new version of the engine (termed the IX), still the same lOO-degree V-4; but now with the . camshaft gear-drive in the failed to start in Finland in July after breaking all the available engines in practice. But a trio of races in August showed the NR was coming good at last; first, Katayama stayed the distance . at the British GP at Silverstone to finish 15th, the first time the bike had ever finished a race. A ,week later. he ' p laced third in a non:title race at Misano amidst a pack of privareers.but still on the rostrum nonetheless. And the next weekend at the German GP on the gruelling Nurburgring, Katayama brought the NR500 home 12th , only two seconds behind Ballington's ill-handling works Kawasaki KR500. Progress was still slow, but after the encouragement of their short 1980 season. Honda threw everything into NR500 development in 1981. A new engine, termed the 2X, was designed, still following the same basic format but with the cylinder angle narrowed slightly to 90 degrees for better balance and more compactness. After originally making their own copy, of the Maxton chassis, Honda now built their own double-cradle steel frame with Pro-Link rear suspension, and sent ~ Katayama off to Europe for a complete the wheels ,off the NR. revving it as high as 22,000 rpm and drifting both wheels in the turns to place as high as fifth amidst all the rival factory two- ' strokes, before sadly pulling out with engine troubles once again. But it was ' an 'im p ressive demonstration of the bike's potential in the hands of a genius rider. However. it was also probably a watershed in Honda's attitude to the NR project. Though power from the 2X engine was now up to 130 bhp at 18.500 rpm, and dry weight down to 297 pounds - ironically, exactly the same claimed , figures as for World Champion Marco Lucchinelli's 1981 RGB 500 Suzuki - Honda reasoned that if even a brilliant rider like · "Spencer couldn't keep up with the leading 500s on a fast circuit like Silverstone" where the high-revving 'NR 's comparative lack of bottom end and midrange power was not so vital, then -th ey had little chance of ever achieving their long-held desire of capturing the: coveted 500cc crown · .with the bike. Accordingly. the diffi.cult decision -was.taken to start work on a two-stroke 500cc GP racer, the NS500, which duly appeared the The first NR500 arrived in April, 1978; though it revved to over 20,000 rpm, it was hard to ride and stalled at under 7000 rpm. center, between the cylinders. By January 1980, this was on test and immediately achieved 120 bhp at 18,000 rpm. already better than the OX version had ever delivered. Under the urging of HIRT team manager Gerald Davison. charged with running the team in Europe, the monocoque chassis was jettisoned in favor of a simpler, more conventional tubular steel frame buill by Honda Britain's chassis guru Ron Williams of Maxton Engineering, around more conventional 18-inch wheels. The result was certainly less avant-garde and, at 319 pounds dry. a lot heavier, but at least now the team could forget about developing a futuristic , chassis and concentrate on the engine knowing that the bike would steer and handle satisfactorily. -Ron Haslam, Honda Britain's lead rider who was Tater to feature more prominently in the NR story, gave the Maxton-framed NR its race debut at Donington in June, but retired. Katayama was now the sole representative in GP racing on the bike, but GP season, though in six rounds he only finished once, 13th in his debut race in Austria. But Honda was widening their horizons with the bike, with factory tester Kiyama placing third in the Japanese GP at Suzuka - then a non-title race - before scoring the machine's long-awaited debut victory in a 200 kilometer event at the same circuit in June; teammate Abe was fourth. The fact that two NR500s could finish such a long race and win it , even at the National level, was a great boost to the project. but even better was to come. At Laguna Seca in July, at arguably America's most prestigious road race, Freddie Spencer rode the bike for the first time and incredibly enough, actually defeated reigning World Champion Kenny Robertson his factory Yamaha in a heat race, though he was to retire in the final with mechanical problems. The decision was taken to replace Katayama with Spencer for the next GP at Silverstone, and in a phenomenal display which few who wit· nessed it will ever forget, Spencer rode following season and in 1983 would give Honda their long-awaited 500cc title. Even then, typically for Honda it was quite unlike anything else being raced currently, a V-3 reed-valve with forward-facing carbs. But the advent of the NS500 did not spell the end of the four-stroke NR project, for by then Honda had begun · to appreciate the long-term technological benefits they were deriving from what had started out as a project with a short-term objective. Accordingly, work continued on the NR500, with a new alloy twin-cradle chassis developed over the winter which featured a return to a 16-inch front wheel, for by then the rest of the GP paddock and, more importantly, tire technology, had caught up with Honda's lead. A revised version of the 90-degree engine, termed the 3X, was fitted to this, and in due course would deliver 135 bhp at 18,500 rpm, but more importantly with a wider power band and more torque. Ron Haslam rode ' the result in three GPs, at Assen, Spa and Silverstone, finishing each one

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