Harley dual sport motorcycle: The Carducci SC3 Adventure

Dual sport motorcycle
Jim Carducci is an engineer with a passion for dual sport motorcycles and the Harley Sportster motor. So he’s put the two together and created the Carducci Dual Sport SC3 Adventure.

It’s not quite as improbable as it sounds, and the amount of engineering on the finished product is quite remarkable. But the question remains: why? “I had a vision of how I could somehow transform a Sportster into a viable dual sport motorcycle,” says Jim. “Others have built variations of the idea, but none suited my eye. And few were truly capable off-road dual sport bikes.”

Dual sport motorcycle
To set the benchmark, Jim rode BMW GSs, KTM 950s and other big dual sport motorcycles. After almost 10 years of thinking about it and talking about it, he started developing the SC3 prototype. “The Sportster motor was the key,” he says. “It produces tractable low-end power and is loaded with torque. Both of which are ideal for dual sporting. Plus, I just love the sound, feel, and look of its V-Twin motor—it has lots of soul!”

Jim bought a 2003 100th Anniversary Sportster “donor” bike—one of the last ‘hard mount’ Sportsters, with a lighter motor than the newer 2004+ model rubber-mounted motors. He then created 2D AutoCAD layouts to lock down the geometry of the frame, motor, suspension, wheels and rider position.

The goal was to get the optimum rake and trail, plus 8+ inches of rear wheel travel and 10+ inches of front wheel travel. The instantaneous force center is now well below the combined CG of the bike + rider—needed for the rear suspension and the traction to work well under acceleration.

Dual sport motorcycle
With the basics sorted, Jim began a 3D solid-model detailed design. He built a full-scale 3D Styrofoam model of the aluminum 6-gallon gas tank (which was hand formed by Evan Wilcox). He also created a billet aluminum swing arm, triple clamps designed to integrate a Scotts steering damper, and vibration-isolation bar risers. Next came a GPS mount, foot controls, a rear fender sub-frame and rack, a crash bar, a fly screen and a skid plate. And last but not least, a kickstand. Corbin made a seat to Jim’s specs.

Dual sport motorcycle
The Sportster motor was upgraded with an NRHS 1250cc kit and Andrews N4 cams. The rest of the components are high-spec too: Öhlins forks and rear shocks, configured to handle the Harley’s weight, plus 18” and 21” wheels from Buchanan’s, with Sun rims and a Talon front hub. The exhaust system is from Supertrapp, Biltwell supplied the 1” diameter handlebars, and the foot pegs are from Joker Machine.

Dual sport motorcycle
Two and a half years later, the bike is more than ready to ride, but Jim isn’t quite finished yet. “I’m currently designing a new exhaust, to make standing up for long periods easier on the rider. I’m also formulating an idea for panniers.” San Jose Harley-Davidson has approached Jim to build bikes for customers, and he’s teaming up with the dealership to get more SC3 Adventures out onto trails and roads around the world.

Top marks to Jim Carducci for going where few others have dared. The Carducci Dual Sport motorcycle might not be an ‘official’ bike, but there’s nothing amateur about this build.

For more on the SC3 Adventure, head over to the Carducci Dual Sport website. Images by Neil Hanshaw.

Dual sport motorcycle