Wildly Addictive: KTM 990 Super Tourer

KTM 990 Super Duke Special from Roman Juriš…  

In 2005, the original KTM 990 Super Duke hit the motorcycling world like a two-wheeled bolt of lightning. Here was a naked bike with a chromoly trellis frame and a 999cc 75° “LC8” V-twin that laid down 120 horsepower and 75 pound-feet of torque. With a short wheelbase, razor-sharp handling, and ferocious brakes, it was a hooligan’s dream.

“There is surely nothing more frenetic on two-wheels than the KTM 990 Super Duke short of sticking a nitrous kit, a jet turbine and a flame-thrower into the frame of a fold-up bicycle.” –MCN

Our friend Roman Juriš spent much of his life under communist rule in his native country of Slovakia, which made it immensely difficult to pursue his motorbiking dreams. Now, in his “middle or slightly advanced age,” he’s making up for lost time with a series of builds quite unlike anything else that lands on our desk. Roman customizes and modifies each bike to serve a riding purpose he has in mind, and the final product tends to look like a special edition the factory itself might have produced.

In the past, we’ve featured his Kawasaki ZR-7 cafe racer, Suzuki SV650 sport special, and Jawa-Suzuki-Aprilia “JSA” supermono. In this case, he wanted to build a trellis-framed V-twin for sport touring…with an emphasis on sport:

“I wanted a sporty touring motorcycle but with lower handlebars that travelers usually don’t like. Because I wanted to ride a bit sporty and a bit touring.”

He picked up a wrecked 2004 KTM 990 Super Duke in Germany and got to work. Roman has an avowed weakness for single-sided swingarms, which the KTM doesn’t have stock, so he came up with quite the ingenious solution for building one of his own:

“I decided to combine two arms into one unit. The part around the pivot and rear shock unit is a KTM original, while the one-sided swingarm with the wheel hub comes from the Honda VFR800.”

The VFR rear wheel is a great match for the standard KTM front wheel, and it’s almost unbelievable how well the solution works! But we shouldn’t be too surprised, as Roman is soon to receive a European patent for a front suspension assembly of his own design. 

The front fairing is based on that of the Suzuki SV650/1000, but with dual headlights. Roman slimmed down the tank for a fresh line and outfitted the cockpit with a Koso dashboard.

The OEM under-tail cans are gone, replaced with an under-engine exhaust more in the style of a Buell, which leaves the tail looking amazingly slim and tapered compared to stock. And then there’s the sound of the fiery LC8 exhaling through the new exhaust line:

“It’s true that the shortened exhaust system isn’t ideal, and there’s a bit of gunfire in the exhaust when you take off the gas, but the sound is wildly addictive.”

The custom saddle and color scheme tie everything together excellently. The bike looks like something that might actually roll out of the KTM factory, if they had a penchant for half fairings and single-sided swingarms.

But this is no show pony. As the photographs below attest, Roman puts some serious miles on his machines.

“The Duke is a brute without…ABS or other electronic toys. It’s riding for real guys who reckon that especially long rides hurt. The reward is excellent riding characteristics and the feeling that only you and no electronics control everything…”

Well said, Roman. Very well said. Below, we talk to the man himself for more details on the build.

KTM 990 Super Duke Special: Builder Interview

• Please tell us a bit about yourself, your history with motorcycles, and your workshop.

I’ve been thinking about motorcycles every day for about 45 years. Except for one big break of about twenty years, when I only thought about motorcycles once a week.

 

• What’s the make, model, and year of the donor bike?

KTM 990 Super Duke, year 2004.

• Why was this bike built?

I have a weakness for V motors and single-sided swingarms. For the new project, I wanted a trellis tubular steel frame with a double-arm stock swingarm and a big V-twin engine up to 1000cc.

Ducati ST2 or KTM Super Duke came into consideration. Finding a suitable donor was not easy. I finally found a crashed Duke in Germany. It was decided.

• What was the design concept and what influenced the build?

I wanted a sporty touring motorcycle but with lower handlebars that travelers don’t like. Because I wanted to ride a bit sporty and a bit touring.

• What custom work was done to the bike?

The original front USD fork is very good; there was no reason to change it. The rear swingarm was a big challenge. I decided to combine two arms into one unit. The part around the pivot and rear shock unit is a KTM original, while the one-sided swingarm with the wheel hub comes from the Honda VFR800.

It’s important to note that the rear wheel from Honda has the same number of spokes and a similar design as the front wheel from the KTM. Therefore, the change does not have a disruptive effect.

I prepared a simple drawing based on the measurements of both swingarms. I removed unnecessary parts from both parts and welded the necessary ones. It may sound unlikely that it can fit, but it really does. Everything was welded up and the part still has the original KTM marking.

 

The second problem was that the Honda is a four-cylinder and the original rear Honda sprocket was not aligned with the front KTM sprocket on the engine. I had to make a combination of a Honda central hub and my rear sprocket flange with a Ducati spocket, because only the Ducati is similarly slim like the KTM. I had a few sleepless nights, but I managed to solve this technical problem as well.

Another challenge was the muffler under the engine. The original Duke has a huge heavy exhaust up the back. Once removed, the rear remained beautifully slim and the bike has a slim silhouette, almost like a single cylinder. It’s true that the shortened exhaust system isn’t ideal, and there’s a bit of gunfire in the exhaust when you take off the gas, but the sound is wildly addictive. And the sound from the exhaust tip is within the noise standard.

I cut down the side “lobes” from the tank to achieve a fresh light line in combination with the front and rear fairings. The front fairing is based on that of the Suzuki SV.

I used a Koso dashboard and I think the seat is another masterpiece from my upholsterer friend.
In the finals, the typical colors for KTM with graphics in my own creation could not be missing.

• Does the bike have a nickname?

My wife calls this bike of mine “the white and orange one.”

• Any idea of horsepower, weight, and/or performance numbers?

The engine is fully stock. Changing the exhaust pipe changed the flow of exhaust gases. It was necessary to fine-tune the map on the dyno.

• Can you tell us what it’s like to ride this bike?

The Duke engine is a brute without balance shafts, and it doesn’t have ABS or other electronic toys. It’s riding for real guys who reckon that especially long rides hurt. The reward is excellent riding characteristics and the feeling that only you and no electronics control everything here.

• Was there anything done during this build that you are particularly proud of?

I’m really proud of the design of the rear swing arm and maybe the fact that the bike looks “pretty” factory.

• Is there anyone you’d like to thank?

To all friends who did a great job welding, painting and upholstery. And to those who didn’t close the door when they saw me coming.

Follow the Builder

I am an occasional correspondent for the Slovak website motoride.sk under the name “Romoto“. Here you will find my articles about motorcycles, written with love and passion for construction and customising. If you have a good translator, you can read more about this bike here, here, and here.

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