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Honda's naked VF800 designs

By MCN -

New bikes

 22 July 2013 08:30

New patents show that Honda is developing a new low-cost, high-spec naked bike around its venerable – but legendary – VFR800 V4 engine.

The bike’s overall design is hinted at in an innocuous-sounding patent titled “Hollow-welded assembled frame structure”, which refers to a fairly technical aspect of how a steel trellis frame can be made.

What’s interesting about the patent isn’t so much the technology it describes but the chassis that’s illustrated in its accompanying drawings. Looking Ducati-esque, it’s wrapped around a motor that appears to be the VFR’s 800cc VTEC V4.

Although the engine is shown only as a simplified outline, since the patent is mainly concerned with the frame, the shape closely matches that of the VFR’s engine and importantly the engine mounts, which define the shape of the chassis, are in exactly the same places.

The frame design is the work of Keisuke Kishikawa, who was the man behind the steel tubular frame of the NC700 series, and Masashi Hagimoto, who’s had a hand in various Honda frames, including the still-born, alloy-framed Moto2 racer.

The idea of slotting the VFR engine into a naked street bike makes a huge amount of sense in the current market.

Such machines have been doing relatively well in sales terms, at least compared to the slump in the sports bike market, with the Triumph Street Triple in particular – along with the ever-popular Ducati Monster – showing that there’s a desire for stylish, relatively inexpensive naked bikes, especially if they steer clear of conventional inline-four engines.

Yamaha’s recently-announced three-cylinder, 850cc MT-09 is the first Japanese bike to be targeted at that Street Triple market.

Outright performance isn’t the key in the naked bike market – most of the protagonists hover a little above the 100bhp mark. That’s largely because the country where this style of machine is most popular is France, where the law still restricts all bikes to 106bhp.

Honda’s 800cc V4 is on the money, power-wise, making 108bhp in the VFR and 101bhp in the Crossrunner. It’s also ideal because it’s not a conventional
inline-four, offering more midrange and character than the more common design.

While a complex engine when compared to inline motors – even ignoring the VTEC system that disables eight of the valves at low revs, there are two sets of cylinder heads and all their associated gubbins where an inline motor has just one – Honda has been making it for so long that it amortised its development costs years ago, allowing it to be financially competitive with newer, simpler engines.

Despite the fact it’s been 12 years since the VTEC VFR was launched, the engine is still a modern design, and it’s particularly useful in this instance because it was always intended to be used as a structural component.

The VFR dates from a period when Honda had a philosophy of separating the swingarm pivot from the main chassis – as on the 929cc and 954cc Fireblades of the early ’00s.

That means the newly-designed steel tube frame for the naked machine, which will presumably be called the VF800, can follow the latest trend for minimalist frames and structural engines. In fact, the frame looks very similar to the trellis on the recently-spied 2014 Ducati Monster 1198.

Although the illustrations here show an oversimplified swingarm design – as with the engine, the swingarm isn’t part of the patent, so it’s only a rough representation – the VFR800 motor has always been used with a single-sided arm in the past.

That would again suit this sort of bike, adding an element of style, and, if it were to share the arm with the VFR and Crossrunner, reduce the cost associated with such a design.

While it’s possible the VF800 will appear as a 2014 model, it could still be more than a year away. Honda’s NC700 was revealed in patent form some two years before it reached showrooms.