The Force V4 onslaught begins with the debut of the VFR400R, a replica of the RVF400 works machine!
Honda's V4 strategy began in 1982. What surprised people was not only the VF750 series, but also the subsequent expansion of V4s into the 400cc class.
Because it was multi-cylinder and high-revving, you could imagine that it would have high peak power, but the public opinion was that the 750 series' flat power feeling and sense of power in the mid-range was superior to the inline-4, which had a long history.
And so, the first-generation VF400F was equipped with a mini-cowl and exposed the V4 engine in an attempt to appeal to the public as a new form of supersport.
However, as expected, it was smooth but lacked excitement, and it never quite gained momentum.
The image of a smooth and orderly V4 engine made people less interested in this engine, but what turned this around was the overwhelming victory of the works RVF400 in an F3 race.
The original advantages of this engine, such as the efficiency of straight intake into the V-bank and a lean engine width of only two cylinders, which gave it far superior maneuverability, gradually brought out its overwhelming potential through development through racing activities.
The twin-tube frame and full-cowl VFR400R was introduced as a replica of the RVF, showing off its overwhelming power and agile, chopping-like cornering!
The V4 engine changed from a smooth 360° crank to a 180° crank with better traction response, which was learned from racing. The valve train also used end-adjustable rocker arms with pillow ball support, which helped reduce inertial mass and straightened the intake port, and perhaps the biggest impact was the use of a cam gear train.
Unlike an inline-4, a V4 cam gear must be equipped with two sets of drive mechanisms. Honda developed a method to fit this assembly, which uses two out-of-phase teeth that eliminate backlash to precisely time the valves, into a cassette, and this advanced mechanism was mass-produced and easy to maintain.
The 55mm x 42mm 399cc engine has a self-imposed upper limit of 59PS/12,500rpm and 4kgm/10,000rpm, but its response, dash power at high revolutions, and the strength of the torque that steadily increases traction during cornering are on par with a 600cc engine... the inline-4 was left completely behind and caught in a trap.
This was largely due to the results of repeated trial and error, similar to the development of a two-stroke chamber, with the adoption of a 180° crank, which combines the exhaust from the left and right V-twin and then brings them together into a single exhaust, a complex arrangement that also involves a sub-chamber.
The frame is also an aluminium twin tube inherited from the RVF works machine. The main part has an eye-shaped cross section measuring 28 x 60 mm with ribs on the inside, and compared to the VF400F pipe frame, it has a significant increase in rigidity, with twice the torsional rigidity and four times the lateral rigidity, while also achieving a weight reduction of 4 kg.
In this way, they were able to dispel the public's image of the V4 and implemented a strategy in advertising to tout its top performance.
With the RVF750 works machine dominating the world market, the Force V4 slogan emphasized the powerful power source and captured the hearts of fans.
Just like the factory machine, it uses a single-supported professional arm that gives it the momentum to pull away!
The V4 truly entered an era of invincibility, and riding on this momentum, the VFR400R moved forward the following year in 1987 with a model change that changed the swingarm to a single-support Pro Arm.
The Pro Arm, which truly symbolizes the replica of the RVF works machine, gained increasing acclaim for its powerful traction, which solidified its position as the most torquey and powerful 400.
Furthermore, a special version was also released in the sponsor's Rothmans colors, which are the same as the HRC works machine that continues to win races around the world, and it continued to attract the hearts of adoring fans.
The VFR400R then rose to the pinnacle of further evolved technology in 1988, called the NC30, and in 1994 it reached its final chapter, with the model name RVF, retaining the name of the works machine.It was a road-going version with almost racing machine specifications, which was a fitting end to the series, but the reckless pursuit of performance without looking back was also one of the Honda characteristics of the replica era.
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Information Source. [ RIDE HI ]