When the big economic crisis struck and the going got really tough for the motorcycle industry, the tough kept going. Honda upshifted and responded like the world leader that it is, redefining the sport to attract a new generation of riders and revitalize the battered old legion searching for a new direction after years of “new-and-improved” machines that have steadily grown more potent and, in some cases, less user-friendly.
Honda started this revolution with a blank screen; nothing stored on an existing hard drive was capable of accomplishing this mission. Besides being a terrific value for the money, the new package had to be highly versatile. It had to show conceptual flexibility. How many variations could be extrapolated from a single design? In this case, there are three: the Integra maxi-scooter and two motorcycles, the naked NC700S and NC700X adventure-touring crossover.
In creating these three machines, Honda has once again surged to the technical/technological lead with a rational project using unequalled synergies to drastically cut production costs without reducing quality. The heart of the package is a compact parallel-Twin with cylinders inclined forward 62 degrees. A massive steel trellis frame tightly “encages” the engine, following its low profile and using it as a stressed member of the same structure.
This design is superbly functional not only for its solidity but also for its highly innovative low profile that leaves plenty of usable space between the steering head and seat. Honda used that space for a false gas tank/luggage compartment; the actual 3.72-gallon tank is located under the seat.
The frame itself is linear, consisting of two 38mm tubes running a curved line from the base of the steering head to the rear of the engine cases. Smaller, 35mm tubes triangulate down to the main spars from the top of the steering head in stiffening-member mode, with additional 35mm tubes mating to the main ones at the bottom of the steering head and running down to the front engine mounts. A pair of 32mm tubes provides further triangulation midway down the main tubes. The structure is clean and has excellent torsional rigidity.
From a geometrical point of view, the rolling gear of the NC700X follows tried-and-true rules, spanning a 60.6-inch wheelbase and sporting rather conservative steering geometry: 27 degrees of rake and 4.33 in. of trail. This same rolling gear is shared by the Integra and naked NC700S. Only difference is that the NC700X stands a little taller than the other two due to its longer-travel suspension: 6.04 in. for the 41mm fork and 5.9 in. for the Pro-Link shock. It follows that seat height goes from 31.1 in. on the Integra/NC700S to 32.6 in. on the NC700X.
On the other hand, the all-new parallel-Twin is the same for all three models. Honda poured a lot of its automotive experience into this project to make the Twin user-friendly and maybe even more “sober” than its other motorcycle engines. It all begins with a 73mm bore and an 80mm stroke for an actual displacement of 670cc. The only other current Honda two-wheel examples of this “undersquare” type of engine design are the VT1300X chopper and little CBF125.
But these types of measurements are rather commonplace on Honda’s automotive side. The smaller bore means more-compact cylinder spacing, making the engine narrower and easier to wrap in a neat frame. Consequent to the smaller bore are the compact combustion chambers, semi-Heron-style, that breathe through four valves of relatively small diameter set at a narrow included angle to further maximize efficiency and reduce fuel consumption.
Distribution is by a chain-driven sohc featuring large base-circle cam lobes to better control and smooth accelerations on the valvetrain. L-shaped rockers have roller-type cam followers to reduce friction. The profile of the combustion chamber is so clean that it only demands 12 degrees of spark advance at idle and not more than 20 degrees at full power. An advanced electronic ignition/injection system takes care of the feeding through 36mm throttle bodies. The manifold for the 2-into-1 exhaust begins immediately downstream of the exhaust ports, inside the head casting.
