HONDA NR750

HONDA NR750

HONDA NR750 in red body paint

The unique Honda 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 Honda  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 was the 748cc V4 engine that was 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 Honda 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.

HONDA NR750

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.

HONDA NR750

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 lightweight materials the NR was heavy, at 4891b (222kg), and accelerated no harder than much cheaper 750cc rival,

HONDA NR750

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