Sunday, 5 February 2017

Honda NR750 (1992) Specification, Review, HD Photos

Posted By: ygshhd 01:41 Leave a Reply

Honda NR750

A stripped-down NR750 revealed the highest level ofstreetbike technology yet seen. Its exhaust system was a hugely complex 8-4- 2-1-2 arrangement with twin high-level silencers in the tailpiece.

A rigid twin-spar aluminium frame and top quality cycle parts gave the XR excellent handling, despite its weight. But on a racetrack it was no more competitive than its NR500 grand prix predecessor.

The unique NR750 was a bike that only Honda, the world’s largest, boldest and arguably also most stubborn motorcycle firm, could have built. Gloriously stylish and technically advanced but complex, heavy and hugely expensive, it was inspired by the NR500 grand prix racer of the late 1970s and early '80s. Like the racebike. the roadgoing NR was most notable for its "oval' pistons, each with two conrods. two spark plugs and no fewer than eight tiny valves.

There was much more to the NR750 than its piston shape. The bike was visually stunning, with a futuristic twin-headlamp full fairing and matching tank-seat unit that was made from a blend of carbon-fibre and fibreglass, and was rumoured to cost more than any other complete mass-produced superbike. The paint finish was outstanding; the titanium-coated screen alone was hugely expensive.

The chassis was of similarly high quality, although its design was relatively conventional. A rigid twin-spar frame of polished aluminium held a Pro-Arm single-sided swingarm. similar to that of the RC30. The front end specification included 45mm diameter Showa upside-down front forks, a 16-inch front wheel, and large twin brake discs gripped by four-piston calipers.

But it w'as the 748cc V4 engine that w<as in every way the NR750’s main attraction. The liquid- cooled. 32-valve motor’s cylinders were set at 90 degrees, with gear drive to the twin overhead camshafts. The eight conrods were made of lightweight titanium. Fuel was delivered by a sophisticated injection system. The complex exhaust system ended in twin high-level silencers in the tailpiece.

The reason for the NR750's existence was that Honda was keen to utilize some of the technology that had been developed more than a decade earlier for the NR500 racer. Back then, there had been a valid technical reason for using oval pistons (in fact they were shaped like a running track, with straight sides and semi-circular ends), following Honda's decision to take on Suzuki's and Yamaha's two- strokes with a four-stroke.

Characteristics of a V8

Honda’s successful grand prix bikes of the 1960s had been high-revving four-strokes, many of them small-capacity multis with four valves per cylinder. By 1979, 500cc GP bikes were limited to four cylinders, so Honda developed the NR as the nearest they could get to a V8. Despite costing billions of yen the ‘Nearly Ready’ was never competitive, and it was abandoned in 1981.

There was no comparable incentive to use oval pistons on a roadster, but the high-revving NR was the world's most powerful 750, with a peak output of 125bhp at 14,000rpm. Top speed was 160mph (257km/h), and the V4 also had an outstandingly broad spread of torque. But despite extensive use of lightweight materials the NR was heavy, at 4891b (222kg), and accelerated no harder than much cheaper 750cc rivals.

Despite its weight the Honda handled superbly, its brakes were powerful and its combination of style and sheer quality of finish made the NR a very special machine for the small number riders who could afford one. But ultimately it is for its looks, technology and price, rather than its performance, that the NR750 will be remembered.

The NR !s rru styling and qualit were worthy of Honda s exotic and hugely expensive technical tour-de-force.

The 748cc V4 engine featured ‘oval' pistons, eight fuel injectors, eight titanium conrods, and 32 valves operated by four gear-driven camshafts.

Race-bred V4: the RC45

Two years after the NR750, Honda produced another exotic 750cc V4 in the RC45, which had a more conventional 16-valve engine and was essentially a follow-up to the all-conquering RC30. Designed mainly as a basis for a World Superbike racer, the RC45 (officially known as the RVF750F) produced 118bhp and was fast, flexible and agile. Although it initially struggled in Superbike racing, and never matched the impact of the RC30, the RC45 earned its share of glory when American ace John Kocinski won the world title in 1997.

Specification Honda NR750 (1992)