KTM 640 Duke II
KTM Duke 640 | |
Manufacturer | |
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Also called | Duke II640, Duke II 640, 640 Duke, 640 Duke II Yellow - Black, 640 Duke II Black, 640 Duke II Red, 640 Duke II Limited Edition, 640 Duke II |
Production | 1998 - 00 |
Engine | Four stroke, single Cylinder. SOHC, 4 valves, engine balancer |
Compression ratio | 11.5:1 |
Top Speed | 162 km/h / 101 mph |
Ignition | Kokusan contactless DC-CDI ignition with advanced system |
Spark Plug | NGK DRBEA |
Battery | 12V 8Ah, maintenance free |
Transmission | 5 Speed |
Frame | Central chrome-moly steel frame |
Suspension | Front: WP - 4054 Roma Top adjuster, preload, compression and rebound adjustable Rear: Central shock absorber WP IBS with PRO-LEVER linkage to rear- swing-arm with needle bearing |
Brakes | Front: Single 320 mm disc, 4 piston caliper Rear: Single 220 mm disc, 1 piston caliper |
Front Tire | 120/70 - ZR17 58H |
Rear Tire | 160/60 - ZR17 69H |
Wheelbase | 1460 mm / 57.5 in |
Seat Height | 860 mm / 33.9 in |
Weight | 145 kg / 320lbs (dry), |
Fuel Capacity | 11.3 L / 3.0 US gal / 2.4 Imp gal |
Manuals | Service Manual |
It could reach a top speed of 162 km/h / 101 mph.
Engine[edit | edit source]
The engine was a Liquid cooled cooled Four stroke, single Cylinder. SOHC, 4 valves, engine balancer. The engine featured a 11.5:1 compression ratio.
Drive[edit | edit source]
Power was moderated via the Multi-disc in oil bath.
Chassis[edit | edit source]
It came with a 120/70 - ZR17 58H front tire and a 160/60 - ZR17 69H rear tire. Stopping was achieved via Single 320 mm disc, 4 piston caliper in the front and a Single 220 mm disc, 1 piston caliper in the rear. The front suspension was a WP - 4054 Roma Top adjuster, preload, compression and rebound adjustable while the rear was equipped with a Central shock absorber WP IBS with PRO-LEVER linkage to rear- swing-arm with needle bearing. The 640 Duke II was fitted with a 11.3 L / 3.0 US gal / 2.4 Imp gal fuel tank. The bike weighed just 145 kg / 320lbs. The wheelbase was 1460 mm / 57.5 in long.
Photos[edit | edit source]
Overview[edit | edit source]
KTM 640 Duke II
AN ANGUISHED HOWL OF RUBBER AGAINST PAVEMENT ECHOES
off the surrounding buildings as the peculiar machine slows for a comer. Tail
hung well out in a controlled brake slide as the fat rear tire scribes a dark
arc deep into the apex. Confident in the bike's capability, the rider dials on
the power and completes the corner in a crossed-up wheelie. A few more hot
laps around the curbed islands and li, poles, and it's time to get out of Dodge
before the sheriff arrives...
Okay, so an occasional late-night romp through a vacant shopping-center
parking lot may not be the most responsible two-wheeled behavior, but are we to
blame for the company we keep? It's a classic case of guilt by association when
a KTM Duke II is your accomplice. "Tlie bike made me do it, officer, honest."'
Since its 1994 release, KTM's street-legal supermotard bike has amassed a
reputation for pavement play. Talk to any sport rider who has crossed paths with
one of these "Dukes of Hazard," and you'll likely hear tales of wild wheelies,
eye-popping stoppies and an uncanny ability to gun down bikes twice its size in
the twisties.
Over the years, the Duke has grown increasingly popular, and has received
minor updates, including an electric starter in '96, and 16cc of added
displacement two years ago. With the Duke II comes further street refinement and
new wrappings that keep step with the current styling of KTM's LC4 off-road
models. Sharper-edged lines have replaced the rounded body contours of its
predecessor, giving the Duke II a more compact and aggressive appearance. Viewed
from the front, the vertically stacked projector-beam headlight array commands
attention, resembling that of the Suzuki Hayabusa and Italian exotics such as
the MV Agusta F4 and Benelli Tornado Tre.
Other updated bits include Italian-made BBS cast-alloy wheels in place of the
previous wire-spoked Akronts. The front rim still measures 3.5 x 17 inches^,
while the rear has grown .25-inch wider to 4.5 x 17 inches. Apart from their
stylish looks-closely resembling BBS's race-car rims-the new wheels are
tubeless. A stout, new 43mm WP inverted fork replaces the old Duke's 40mm legs,
and there's a stiffer swingarm, too.
A tush tuck has cleaned-up the Duke's tail, as the bike now shoots from both
hips with dual muffler cans positioned, Ducati 996-style, beneath its seat. The
double-barreled arrangement recalls the Vickers machine guns mounted on the
business end of a Sopwith Camel. Backroad dogfighters beware!
It may sound like tall talk coming from a rider astride a humble 626cc
Single, but the Duke's off-road-bred chassis makes it a fierce scrapper on its
home turf. Loads of cornering clearance, grippy Bridgestone BT93 Battlax
radials, tractable power delivery and no small helping of attitude are the
ingredients for setting a blistering pace through any tight series of
switchbacks. And if the road surface suddenly rums bad, no problem-the Duke's
suspension eats up bumps and potholes like few streetbikes can.
Unlike a conventional long-travel dual-sport machine, the Duke II makes do
with just 5.5 inches of front-wheel movement and 6.7 inches at the rear. With
its spring and damping rates calibrated for road work, fore-and-aft chassis
pitching is minimal. The only handling quirk we encountered was fair bit of fork
dive when the front brake was suddenly applied while leaned over in a corner-not
a recommended riding practice by any means.
But when it comes to dealing with a dicy situation, the Duke II has the
instincts of a cat. The wide Magura tapered-aluminum handlebar and dirtbike-inspired
riding position instill an uncanny sense of control when ridden to the limit,
even over the roughest pavement. And wet road conditions? Pour it on!
As for negotiating urban traffic, riding the KTM is like having the keys to
the city. Its 35-inch-high seat provides a clear line of sight over the tops of
cars, yet it's low enough for riders of average inseam to find a firm footing at
stops. And the bike's light weight, coupled with torque-rich power delivery
right off the bottom, gets the drop on the rush-hour rat race every time.
Ride a Duke about town for long, and you begin to perceive your environment
differently. A raised manhole cover is no longer an obstacle to avoid, but a
chance to catch some free air! Ditto for speed bumps or sudden elevation
changes. Low-traction surfaces add another fun element to any urban hard-cross
course.
Pulling wheelies is simply a matter of rolling on the gas in low gear or
snapping the throttle open along with a light tug on the bar in second. True,
the KTM is no match for multi-cylinder sportbikes in straight-line acceleration,
but among its one-lunged peers, the Duke makes no apologies. Its liquid-cooled,
four-valve, four-stroke engine churned out 49 horsepower and 42 foot-pounds of
torque on CfFs rear-wheel dyno. Accelerating through the slick-shifting
five-speed gearbox is swift and effortless, evidenced by its 99-mph quarter-mile
trap speed and gearing-limited, 108-mph top speed. At freeway speeds, there is
more than enough juice in reserve to cleanly pull roll-on passes without kicking
it down a gear.
A gear-driven counterbalancer helps keep engine vibes at an acceptable level.
At lower revs, the power pulses are soul-stirring, but as engine speeds exceed
5000 rpm-an indicated 75 mph in top gear-a high-pitched buzz develops, making
long freeway hauls taxing. The stylish mirrors provide very good views to the
rear, but are inflicted with a healthy buzz. A good practice is to periodically
pull in the clutch and let the revs fall to idle, and then check your mirrors
for the fuzz.
In fact, hanging onto your driver's license is quite probably the greatest
challenge you'll face as a Duke II owner. While speeding citations are the bane
of any sport rider's existence, Duke riders are just as likely to rack up
"exhibition of speed" or "reckless driving" charges.
Best of luck with the-Duke-made-me-do-it defense. If all else fails, plead
insanity. S
Source Cycle World 1999
Make Model | KTM 640 Duke II |
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Year | 1998 - 00 |
Engine Type | Four stroke, single Cylinder. SOHC, 4 valves, engine balancer |
Displacement | 624.6 cc / 38.1 cu in |
Bore X Stroke | 101 x 78 mm |
Compression | 11.5:1 |
Cooling System | Liquid cooled |
Lubrication | 2 x Eaten oil pumps |
Induction | Mikuni BST 40 carburetor |
Ignition | Kokusan contactless DC-CDI ignition with advanced system |
Starting | Electric & kick |
Spark Plug | NGK DRBEA |
Battery | 12V 8Ah, maintenance free |
Max Power | 40.1 kW / 55 hp @ 7000 rpm |
Max Torque | 60 Nm / 6.1 kgf-m / 44.3 lb-ft @ 5500 rpm |
Clutch | Multi-disc in oil bath |
Transmission | 5 Speed |
Primary Drive Ratio | 30:81, straight cut gears |
Gear Ratios | 1st 14:35 / 2nd 15:24 / 3rd 18:21 / 4th 20:19 / 5th 22:18 |
Final Drive Ratio | 17:38 |
Final Drive | Chain, O-ring 5/8 x 1/4" |
Frame | Central chrome-moly steel frame |
Front Suspension | WP - 4054 Roma Top adjuster, preload, compression and rebound adjustable |
Front Wheel Travel | 140 mm / 5.5 in |
Rear Suspension | Central shock absorber WP IBS with PRO-LEVER linkage to rear- swing-arm with needle bearing |
Rear Wheel Travel | 170 mm / 6.7 in |
Front Brakes | Single 320 mm disc, 4 piston caliper |
Rear Brakes | Single 220 mm disc, 1 piston caliper |
Front Tire | 120/70 - ZR17 58H |
Rear Tire | 160/60 - ZR17 69H |
Steering Head Angle | 62.5o |
Wheelbase | 1460 mm / 57.5 in |
Ground Clearance | 250 mm / 9.9 in |
Seat Height | 860 mm / 33.9 in |
Dry Weight | 145 kg / 320lbs |
Gvwr | 350 kg / 773 lbs |
Engine Oil Capacity | 2.2 L / 2.3 US qt / 1.9 Imp qt |
Fuel Capacity | 11.3 L / 3.0 US gal / 2.4 Imp gal |
Standing ¼ Mile | 12.5 sec |
Top Speed | 162 km/h / 101 mph |