THE CULT CONTINUES
On the basis of the new LC4 engine generation, it’s time to write the next chapter of this one-cylinder success story: KTM presents the 690 Duke, the ultimate single-cylinder naked bike! It’s driven by the most powerful, 65 HP (48 kW), street-legal single of all time, equipped with a superior street suspension and assembled with a discernible passion for design and technology. The new Duke unswervingly takes the KTM company’s total idea to the streets.

A trendsetting tubular space frame design
Superior suspension components from WP
Stable ergonomics
Universal capabilities
State of the art LC4 engine technology
Unrivalled performance
Minimal weight
Fascinating design

CHASSIS

FRAME
A supremely innovative and super-sturdy tubular space frame. Developed using the latest analysis and simulation technologies, its construction from thin-walled chrome-molybdenum tubes guarantees maximum torsional rigidity for excellent tracking stability at a minimal weight (just over nine kilos).

WEIGHT
Thanks to consistently lightweight construction and enormous development efforts, we were able to keep the 690 Duke models “Ready to Race” weight at the unparalleled low level of 148 kilograms (without fuel).

CHASSISFully adjustable, 48-mm USD forks from WP guarantee excellent damping, a high degree of tracking stability and sufficient damping reserves.
A high quality WP shock absorber with an integrated compensation tank is installed at the rear and supported by a Pro-Lever linkage system.  Both the compression and the rebound damping, as well as the spring preload can be adjusted for their intended purposes. At 140 mm both front and rear, the suspension travel is suited to the needs of asphalt riding.

SWINGARM
A one-piece, aluminium die-cast swingarm. Its contour was modified to conform to the bending moment curve using special ribbing and various wall thicknesses, to give it optimal torsional and flexural rigidity in conjunction with the lowest possible weight. A Pro-Lever linkage provides the shock with a progressive pivot point and permits the ideal positioning of the shock absorber.

BRAKES
Brembo components throughout guarantee maximum deceleration under any conditions: a 320-mm floating disc combined with a radially bolted four-piston fixed caliper and four single linings ensure excellent application and high reserves at the front. The rear wheel is reliably stopped by a single-piston caliper and a 240-mm brake disc.

AIRBOX
Imbedded in the compact rear subframe, the large-volume airbox stands for high performance, which, in combination with a long intake snorkel, also ensures efficient sound absorption.
EXHAUST SYSTEM
Its innovative exhaust system was and is typical for the Duke. So the exhaust gases of the 2008 Duke are released through an elaborately conceived silencer on the underside of the motorcycle. This underfloor-principle combines several advantages. Along with an optimal output yield and its advantageous location for the bike’s centre of gravity, the silencer’s large volume ensures a minimal noise level and the regulated catalytic converter ensures compliance with the EURO III exhaust emissions limits.

SEAT
A slightly graduated seat offers the rider a low seat height of 865 mm and at the same time the best control and good contact with the handlebars. The passenger also has a comfortable seat behind the pilot.

BODYWORK
Even though it’s a completely new motorcycle, the 690 Duke is instantly recognizable as a KTM and as a descendant of the legendary Duke single-cylinder. Puristic solutions, elaborate details and the unmistakeable characteristics of a KISKA design make this extremely slim, single an eye-catcher in traffic. Especially typical: the ultra-compact front mask with two, mini halogen headlamps mounted one above the other. Along with the KTM brand colours orange/black, the new 690 Duke is also available in white/black.
COCKPIT
The especially lightweight multifunctional instrument is equipped with an analogue tacho and a digital speedometer, plus numerous additional functions to provide all the necessary information.

ENGINE

The powerful heart of the new 690 Duke is the ultra-modern LC4 engine with 654 cc, which is currently serving as the role-model in the large-volume, single-cylinder, four-stroke category. It distinguishes itself through state-of-art technology, low weight, its very compact construction and above all through its outstanding performance data, attaining a maximum of 65 HP (48 kW).

OHC CYLINDER HEAD
An overhead camshaft operates the four valves (extra lightweight, hollow-shafted valves on the exhaust side) by means of two weight- and rigidity-optimized rocker arms. In combination with the compact combustion chamber, this construction makes incomparable performance and the greatest reliability possible, as well as making servicing simple, due to the slanted fitting of the cylinder head cover.

CLUTCH
The APTC anti-hopping clutch efficiently prevents the rear wheel from chattering during braking. Under load, the system increases the pressure on the clutch linings, whereby the hardness of the clutch springs and consequently the hand grip strength needed to operate the hydraulic clutch were able to be significantly reduced in comparison with conventional systems.
ENGINE MANAGEMENT
The LC4 engine is supplied via an electronic injection system, which features a 46-mm throttle plate cross-section, automatic cold start, idle-speed regulator, lambda control and altitude compensation. The EPT System (Electronic Power Throttle) produces a very homogenous power output, because the position of the throttle plate is electronically controlled in addition to the manual operation of the throttle.

BALANCER SHAFT
A central balancer shaft effectively reduces vibrations to a minimum.

Foto: R.Schedl