Honda reentered Grand Prix motorcycle racing with a bang in 1979, following a 12-year hiatus. At a time when two-stroke engines dominated, Honda did what Honda does best and went its own way, developing a 500-cubic-centimeter four-stroker unlike any before. Its V-4 architecture featured oval pistons allowing two connecting rods and eight valves per cylinder, effectively creating a powerplant that functioned like a V-8. It was a brilliant—if not batty—effort to match the higher output of equivalent two-stroke engines of the day while adhering to rules that stipulated no more than four cylinders.

"When I look back at it, I'm not sure if we were experimenting with cutting-edge technologies or obsessed with foolish ideas," recalls Toshimitsu Yoshimura, an engineer involved in the development of the NR500's oval piston engine. "At least we were doing something that was beyond the realm of conventional thinking. I'm not just talking about us, who were designing the engine, but also those who were creating the body.”

The body featured an aluminum semi-monocoque frame with inverted forks. Plagued with issues, as is often expected of nascent technology, the pressure to win ultimately won out and so the NR500 was soon shelved in favor of a two-stroke equivalent called the NS500.

Inspired by the daring project, Honda engineers would revisit the oval piston engine and eventually perfect it 13 years later, this time for street application, in the NR750. Displacing 747 cubic centimeters and featuring computer-controlled, multi-point fuel injection, output reached an impressive 125 horsepower at 14,000 rpm. Even with its lightweight carbon-fiber bodywork, titanium connecting rods, and cast magnesium wheels, it tipped the scales at a portly 491 pounds dry. Indeed, it is said to be the first production sportbike to feature carbon-fiber panels, side-mounted radiators and exhaust outlets exiting under the seat. Even its windscreen was exotic, coated in titanium. Unsurprisingly, the 1992 Honda NR750 was the most expensive production motorcycle in the world, selling for $50,000 when new.

This NR750 entered the Dare to Dream Collection in 2014. Though its history is not presently known, it appears to have been highly prized by its former owner as it has been under current ownership, remaining remarkably well-preserved. With only some 322 examples said to have been produced from 1992 to 1994, most have long disappeared into collections with examples like the one offered here rarely breaking cover to reach the market.