When you're in the market for a light motorcycle (as in light weight), a single cylinder dual sports or supermoto-style bike is an interesting choice. These are usually easy to ride, don't have a lot of horsepower, and don't cost a lot of money. Well that may be true for some, but it certainly isn't true for the KTM 690 Duke. This is a serious sports bike in a small package, with a cool design and price tag to match!

KTM is an Austrian motorcycle manufacturer that's mostly known for its off-road bikes. Sounds new to you? Well, the company has been making motorcycles since 1954, won the Paris-Dakar rally eight times in a row, and raced in the GP 250 and 125 classes. They even make a car (well, it has four wheels). The 620 Duke was designed in 1992 and can be seen as the world's first 'funduro' - derived from an enduro chassis and engine, but made to have fun on the streets!

690 Duke
The 2008 and later 690 Duke is the third variation on the theme and thoroughly modern. The machine is available in black, black with white or black with orange, the latter being KTM's colour of choice. There’s minimal but beautifully styled bodywork around the dual headlights, rear frame section and exhaust. The cockpit is minimal with an analogue rev counter and a digital display for the speed, coolant temperature and – handy, a clock! In fact, everything about the bike is minimal and functional. You will not find anything on the Duke that isn't absolutely necessary.

Tech stuff
The engine is a single cylinder 4-stroke with a 654cc displacement and a counter-balancer to prevent too much vibration. It’s an 'overbore' design (102x 80 mm), keeping the revs relatively low and the engine in one piece. Power output is very impressive for a single cylinder: 48 kW/64HP and a torque of 67 Nm (almost 50 lb-ft). Because single cylinders and V-twins can experience rear wheel chatter during aggressive (or clumsy) downshifts, KTM uses a slipper clutch.
The sub frame, kickstand, handlebar and wheels are all made out of lightweight aluminium. The wheels and front axle are hollow, the swing arm is open on the sides and there is only one front disc brake. Together with the single cylinder engine and minimal bodywork, that leads to a dry weight of only 148.5 kg (327.4 pounds). That's not a supermoto, that's a supermodel!
Luckily you don't have to be a tall supermodel yourself. The seat is 865 mm off the ground, and although not very low, its lower than the Aprilia Dorsoduro or the BMW F800 GS. Since the bike is so narrow and light, you will have little fear of tipping over.

First impressions
The KTM Duke looks almost like a one-off product by a custom builder. It uses very high quality parts: adjustable clutch and brake levers, a nice handlebar, fully adjustable WP suspension, Marchesini wheels and Brembo brakes. Speaking of brakes, there may be only one front brake (to save unsprung weight), but it's a radial-mount four-piston Brembo calliper with a stainless-steel brake line. This will out-brake your boyfriend's bike for sure!
The exhaust is mounted under the engine and surprisingly quiet. There doesn’t seem to be much of a fuel tank. It's mounted low and partly under the seat and holds 13.5 litres or 3.56 gallons. Not much, but since fuel consumption is very reasonable you can still get almost 300 km or 200 miles between fuel stops.
The seat is the strangest part of the machine. It feels very slippery when you're wearing jeans. Well, just wear leathers then like you're supposed to! There are two humps that you can sit back against on the highway or during acceleration. And this seat is hard, very hard. But there is enough room and usable grab rails for a passenger-if you can find someone brave enough to be your pillion.

Riding
The Duke is probably the exact opposite of the BMW F650 GS from a previous MOTORESS test I quote: "The F650GS riding experience is smooth, chic, silent—a calm running engine". Well, this is neither smooth nor calm running. Although as noted, the exhaust is (too) quiet. The 690 engine wants to perform like an Arabian horse pulling at the reigns. It doesn't like low revs very much, but puts up with it. With every twist of the throttle, the KTM jumps forward with enthusiasm. Having said that, the engine is actually quite usable in city traffic. It can pull away from traffic lights smoothly and shifting is easy.
The engine does not vibrate much around town. The mirrors remain clear up until highway speeds. But over about 115 km/h (70 mph), vibration sets in and makes it very clear that you're on a big mono. I had no problems riding on the highway, but since the machine it so light and quick-steering, it will need more rider input to holds its line.
Of course, there is only one territory where the KTM 690 Duke feels right at home. And that's curvy backroads. The narrow frame, sporty tires, excellent suspension and bravely braking Brembos work together to give you the most control you've ever felt on a motorcycle. I mean, you can not only aim it to hit a dime in the middle of a corner, but you can also feel which side is up. The power from the engine is really remarkable and it sometimes even feels faster than KTM's 990 V-twin. Thus, it is easy to start feeling invincible and go into turns too fast. Then you discover that you can always lean in deeper. The steering is so quick that it's easy to adjust your line mid-corner.

Conclusion
Sorry if I got a little carried away on the riding part. Aren't there any disadvantages then? Yes, lots. There are no accessories for this bike, apart from 'power parts' that are even lighter. The seat is too slippery and hard and it can be too high for some ladies. The handlebar pushes your elbows out in an 'attack mode' which isn’t too comfortable. The rear spring has way too much preload. The engine vibrates at higher speeds and you'll need to work the 6-speed gearbox to keep the bike moving gracefully.
That's a lot of disadvantages- question is do I still want one? YES!
Even at MSR price of USD10,898.

For more information on KTM products or to find a dealership near you, visit their website.

Author: Cynthia Zijlstra; Photos by Onno Poelmeyer