Maximum
Twin-Cylinder Motorcycles:
Honda VTX 1800N vs. Kawasaki Vulcan 2000 vs. Yamaha Road Star 1700
We take the
biggest motorcycle V-twins—Honda's VTX1800N, Kawasaki's Vulcan 2000, and
Yamaha's Road Star 1700—for a big ride to Texas (of course) where we discover
big fun and big surprises in Big Bend National Park. From the April 2004 issue
of Motorcycle Cruiser magazine.
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Photography by Marc Cook and Kevin Wing. |
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Big Bend is a cross between Zion and Death Valley. |
The parameters of the test were simple:
Street-styled cruisers with a V-twin engine displacement of at least 1700cc. (It
is a brave new world indeed when 1500cc V-twin bikes can be thought of as
middleweights. Expect a Motorcycle Cruiser test of the 1500/1600cc cruisers to
follow shortly.) All three of the big, big twins to make the cut were,
coincidentally, new or much-improved bikes for 2004. The players were Yamaha's
overhauled Road Star 1700, with its pushrod twin the only engine here that's
air-cooled and carbureted. Honda's eye-catching, Rune-influenced VTX 1800N
(Neo-Retro) brings an 1800cc, liquid-cooled, fuel-injected design and a single
overhead camshaft design, while Kawasaki's ultimate gunslinger, the V2K—which
invokes serious piston envy at a whopping 2000cc—is another pushrod, but
unlike the Yamaha, it's liquid-cooled and injected. Oh yeah, we invited the
Harley Custom Vehicle Operations' (CVO) Screamin' Eagle Ultra Glide, with the
factory's first fully endorsed 1700cc air-cooled Twin Cam, along for kicks. But
since that bike is a full-boat touring machine—not to mention virtually
unobtainable at nearly $30K, and with only 3200 units being produced—it really
didn't fit a slot that matched our other pegs.
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We made our usual stop at I-10's "The Thing," but didn't
buy any snakeheads this trip. |
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These overlooks, such as here on Highway 170 and below right in Big
Bend looking across at Mexico,, were good for a sensory buzz. Here
Friedman demonstrates why his title for the April 2004 issue was Drain
Plug Washer. |
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The Honda's flush, Rune-like chevrons and bullet turns are as trick
as can be. Most customs aren't this cool. |
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While the Kawasaki taillight is bulbous and somewhat ugly, it is
also the one that's the most visible at night. |
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The new-for-2004 white lens covers on the Road Star drew mixed
reviews, both for style and visibility. |
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Instrumentation varies only in the details. The Honda's needs some
upgrading when compared to the others. |
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The V2K's instrument cluster was reasonably easy to take in at a
glance, has more features, and an elegant style. |
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The Star's pod has a nice white-face retro feel but is set so far
back that you must drop your head to view it. |
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Power follows displacement in this trio, with the Kawasaki making
more power everywhere than the Honda and the Honda similarly out-pulling
the Yamaha. |
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Aside from size, the VTX 1800's engine is an almost typical Honda
cruiser V-twin. That is, it employs Shadow-like technology in the split
crankpins—the connecting rods meet the crank at two slightly skewed
positions, not side by side as on the other V-twins here—which helps
reduce vibration significantly. (Split pins create other types of
vibration in smaller amounts, but aren't nearly as annoying as the large
primary imbalance of a narrow-angle—in this case 52-degree—V-twin.)
This scheme makes the engine act more like a 90-degree V-twin, which has
perfect primary balance. What vibration escapes the split crankpins and
the massive, 41-pound flywheel assembly is counteracted by a gear-driven
counterbalancer, while driveline shocks are taken up by three sets of
dampers, one on the crank end and two in the clutch. Twin-plug combustion
chambers are fed by three valves each, two intake and one exhaust, long a
Honda hallmark for engines intended to produce little high-rpm power.
Unlike the Kawasaki and Yamaha, the Honda uses chain-driven single
overhead cams. Generous cooling fins suggest otherwise, but the VTX is in
fact liquid-cooled. If you're wondering, the actual redline is 5750 rpm. |
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Kawasaki pulled out all the stops to make the biggest production
V-twin going. With a 103mm bore and 123.2mm stroke, the Vulcan's engine
the largest production V-twin and the most undersquare of this bunch, with
a bore/stroke ratio of 0.83:1. (Honda's is 0.89:1; the Yamaha is 0.85:1. A
typical sportbike's ratio is around 1.5:1.) Generally, a long-stroke
engine builds torque strong and fast, as the Vulcan does with a vengeance,
peaking at 121.4 foot-pounds, 16.8 foot-pound above the Honda. Its four
valves per cylinder—chosen most likely as much to provide additional
heat paths through the valves as for their breathing ability—are
operated by four pushrods and two cams located in the right engine chest,
as Harleys have done forever. Pushrods? On a brand-new design? It makes
sense, actually, if you intend to keep the engine as short as possible, a
task made tougher by the long stroke. Besides, the rev limit on this
engine (actually 5000 rpm) is set by maximum piston speed, which in turn
dictates a redline well within the capabilities of a modern pushrod valve
train. Hydraulic lash adjusters make the valve train maintenance-free. and
Kawasaki's usual excellent gear-driven counterbalancer helps flatten the
considerable vibes inherent in this design. |
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On a bike intended to house a classical rendition of the V-twin
cruiser motorcycle engine, the Road Star's mildly tuned air-cooled
powerplant makes a bit of sense. For 2004, Yamaha increased the bore to
match the specification of the Road Star's Warrior stablemate, at 97mm,
giving this Road Star engine the same total displacement of 1670cc. Yes,
it's the smallest engine here, but that's not why its power lags behind
the two bigger bikes we pitted it against. Simply put, the Road Star's
48-degree, air-cooled V-twin engine has very mild camshaft timing, four
small valves per cylinder, and must breathe through a single 40mm
carburetor. That's partly why the Road Star's engine, at 61.1 horsepower
and 93.1 foot-pounds of torque, dramatically lags behind even its Warrior
brother, which, thanks to fuel injection, hotter cams and a
freer-breathing exhaust system, pounds out 76.3 hp and 97.9 foot-pounds of
torque, and has a 1000-rpm-higher redline to boot, even though its basic
engine specifications are the same as this Road Star's. Yamaha is keenly
aware of the gap, and we are fairly sure the company has something afoot,
either hot-rodding or a new injection of good old displacement, to remedy
this situation and achieve parity. |
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2004 Honda VTX 1800N |
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2004 Kawasaki Vulcan 2000 |
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2004 Yamaha Royal Star |
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