By Red Rider Magazine staff
In the vernacular of the Honda Way, an “old” motorcycle model is one that has weathered the ebb and flow of engineering fads and matured in the only way possible for a Honda product: continual rebirth. When that machine is Honda’s revered Interceptor®, each four-year evolution has transformed it in a way that ensures the latest generation is always in its prime. Such is the case with Honda’s sixth-generation Interceptor, an athletic sporting motorcycle that is in the bloom of its best years.
Honda has made no secret of the fact that the Interceptor is a rolling showcase of the company’s substantial technical prowess. Whereas the original 1983 Interceptor debuted liquid-cooled V-4 power, a sturdy box-section perimeter frame, a single-shock rear suspension and an anti-dive front suspension, the latest iteration showcases VTEC® (Variable Valve Timing and Lift Electronic Control) cylinder head technology, advanced programmed fuel injection (PGM-FI), a triple-box-section “pivotless” twin-spar aluminum frame, a Pro Arm® single-side cast-aluminum swingarm mounted to the engine, a Pro-Link® rear suspension with a 40mm gas-charged Honda Multi-Action System (HMAS) shock, a 43mm HMAS cartridge front fork, a Linked Braking System (LBS) and optional antilock brakes (ABS). As on the cutting-edge 800cc V-4-powered HRC RC212V now competing for the world championship in MotoGP, every system on the Interceptor is integrated into the whole and works seamlessly as one tool. One ride is all it takes to make a believer.
Climb aboard the standard Interceptor or the optional ABS version and the bike immediately fits like a well-worn leather jacket. Belying traditional sportbike ergonomics, the seating position is nearly upright with a slight forward reach to the clip-on handlebars and adjustable levers. The footpegs are located a reasonable knee-bend below the well-padded saddle, perfect for taking weight off the lower back and well-suited for body maneuvering during spirited riding.
Thumb the starter and the fuel-injected 781cc DOHC 90-degree V-4 snarls to life, quickly settling into a burbling idle that tells you there’s a lot more on tap when you’re ready. Slip the six-speed transmission into gear and you immediately notice the smooth and instantaneous power delivery of the V-4 configuration. Thanks to Honda’s VTEC design (see sidebar), the Interceptor engine delivers extremely tractable power right off idle and well into the meat of the torquey power band. At 6400 rpm, it sheds its Clark Kent suit and becomes a fire-breathing Nomex-clad Superman capable of keeping pace with more tightly focused sportbikes.
In VTEC mode, the rider knows instantly that the engine has shifted from two-valve to four-valve operation. A blood-stirring howl emanates from the intake and exhaust, and the grin-inducing power makes itself felt immediately. The delivery of this faster-than-a-speeding-bullet brawn is smoothed by subtle adjustments to the digitally controlled ignition timing and fuel-injection mapping. Revving beyond 6400 for the cammy rush becomes a bit of an addiction, yet the real magic of the Interceptor is experienced in many subtler ways.
In daily operation, the Interceptor feels as though every rough edge has been polished to a CNC-like finish. The carefully calibrated, preload-adjustable HMAS front and rear suspension deliver mile after mile of highway comfort. The wind-tunnel-derived fairing efficiently diverts engine heat, turbulent air and inclement weather away from the cockpit yet still permits a cooling flow to reach the rider’s upper torso. For all-day rides that soldier on past sunset, four multi-reflector headlights provide brilliant nighttime illumination. When it’s time to slow, the LBS does a marvelous job of settling the suspension with just a modest application of the front brake lever. When a rapid stop is required, full application of both brakes brings forward motion to a halt with little drama. For those wishing for a greater cushion of safety, the Honda Interceptor ABS model brings to bear the most advanced antilock brake system in production.
Honda’s Interceptor has always been a looker, and there’s a lot to drool over. From the high-tech instrument display to the beautifully cast single-sided Pro Arm swingarm to the NR-style center-up exhaust with twin stainless steel mufflers, the Interceptor shows as well as it goes. In 2007, a 25th Anniversary Edition served up a tricolor Pearl Blue/Pearl White/Red paint scheme, black-painted wheels and frame, and special tank badging, with Candy Dark Red as another option. Like a tip of the hat to the original 1983 Interceptor, it’s really good to see our friend again.
Sidebars: Remembering the First Time
Those lucky enough to have had the chance to ride a 1983 VF750F Interceptor recall the moment as if it were their first home run, touchdown, goal, race win, conquest—name your transcendent moment. Honda’s sporting V-4 packed a lusty punch, and its track-inspired fairing, 16-inch front wheel, rectangular-section perimeter frame, single-shock rear suspension and anti-dive front suspension made it the belle of the ball. It delivered too. With the first liquid-cooled engine in any sportbike, the Interceptor’s 90-degree V-4 spun out an amazing 86 horsepower, making the bike quicker through the quarter-mile and faster on top than any of its peers. It dipped easily into turns and torqued mightily through exits, and the wail of its 749cc V-4 seemed to telegraph its approach. In AMA Superbike racing trim it also excelled. In its rookie year the VF750F won eight of 14 nationals and started a legacy of Honda V-4 dominance that endured for nearly two decades.
A VTEC Primer
The goal of VTEC is to keep the air/fuel charge moving at a high velocity—in the neighborhood of 350 to 450 feet per second—on its way to filling the cylinder. The faster the charge moves, the more air/fuel gets stuffed into the cylinder—and that means more power. In a four-valve head, high charge speeds are easy to maintain at high rpm because as the piston moves down rapidly it pulls the mixture into the cylinder quickly. But at lower engine speeds the charge velocity drops and therefore the cylinder doesn’t fill as efficiently. By eliminating the operation of two of the four valves (one intake, one exhaust) at lower engine speeds, VTEC “narrows” the path to the cylinder; this keeps intake charge velocity high, ensuring crisp throttle response and ample low-rpm power.
Honda was the first company to offer variable valve technology with the introduction of the 1983 CBR400F with REV (revolution-modulated valve control) in the Japanese market. As the precursor to VTEC, the system delayed the opening of two of the four valves, allowing engineers to tune the two-valve low-rpm power curve for torque and the four-valve, high-rpm power curve for horsepower. On the Interceptor, the V-4 engine runs on two valves per cylinder below 6400 rpm and then switches to four valves per cylinder, delivering significantly stronger low-end and mid-range torque while maintaining the Interceptor’s impressive high-rpm power delivery. The Interceptor also features a solenoid-actuated dual-air-intake-duct design that keeps one duct closed during low-speed operation. Like the two-valve/four-valve system in the engine, this one-duct/two-duct system keeps intake velocity speed high as well.
In operation, the Interceptor’s camshafts act directly and continuously on one intake and one exhaust valve per cylinder. Above 6400 rpm, a special oil spool valve actuated by an electric solenoid sends oil pressure to a hydraulically actuated lifter sleeve inside the inverted buckets of the direct-actuation lifters. This positions a spring-loaded engagement pin above each valve stem of the two unopened valves. Consequently, the two previously disengaged valves now open and close together with the direct-actuation valves, and the engine functions in a conventional four-valve manner. At all engine speeds, camshaft lift, timing, duration and overlap remain constant.
Originally Published in the December 2009 issue of Red Rider Magazine.