Carducci Dual Sport Sportster Conversion

April 8, 2014
Byron Wilson
Byron Wilson
Associate Editor|Articles|Articles RSS

Byron's sure to be hunched over a laptop after the checkers are flown, caught in his own little version of heaven. Whether on dirt, street or a combination of both, MotoUSA's newest addition knows the only thing better than actually riding is telling the story of how things went down.

For some, imagining what it would take to get a Harley-Davidson outfitted for dirt duty may seem a pointless exercise. There are plenty of off-road and adventure motorcycles out there which can suit just about any rider’s need after all. For others, though, the question nags incessantly until something is done.

Not long ago Jim Carducci became tangled in such thoughts, conceiving a Sportster in full dual-sport trim that was capable of more than just a quick jaunt down a gravel road. Since then he’s dedicated significant time designing, building and testing his prototype; the result is the Carducci Dual Sport SC3 Adventure.

Carducci earns his bread as an Engineering Director in the semiconductor industry, designing high-tech pieces in CAD programs out of billet aluminum, steel and plastics. This ideal background helped him start almost from scratch, comparing the design geometry of the Sportster’s frame and engine against other larger-bore adventure bikes on the market.

“If you pitch the frame in the right direction, pull the rake in, extend the swingarm to a certain point and get the travel right all of sudden the geometry looks right,” explains Carducci. “I got to a point where it looked like it was going to work so I gave it a shot.”

He decided to focus specifically on Harley-Davidson Sportsters (both the 883 and 1200) from 1993-2003 primarily because the Motor Company hadn’t yet employed rubber mounts for the engine.

“I didn’t want to do a conversion on a rubber mounted motor,” says Carducci. “It’s a little bit heavier and plus dealing with the motor moving around like that I figured you’d lose feel with that kind of an off road bike.”

One of the first pieces he designed was the swingarm, a CNC machined, billet aluminum piece that has garnered a lot of attention from onlookers since Carducci began taking the SC3 Adventure on the road.

“It’s lightweight, strong, torsionally stiff and longer than the stock Sportster swingarm but it weighs about the same,” says Carducci.

Ohlins built the forks and shocks to specification for the SC3 Adventure.
Only a few pieces of the original Sportster remain  besides the frame and engine Carducci kept the switches and hand controls as well.
(Above) Ohlins built the forks and shocks to specification for the SC3 Adventure. (Below) Only a few pieces of the original Sportster remain, besides the frame and engine Carducci kept the switches and hand controls as well.

He then focused on adapting the front end, foot controls, foot pegs and levers to get a prototype built. In the early days he sourced a number of parts from aftermarket companies to get a working proof of concept ready to roll in six months’ time. From there he continued to design parts, creating 3D CAD drawings of a custom triple clamp, exhaust and hand-forged aluminum gas tank. The tank, like the swingarm, is a feature Carducci takes particular pride in, explaining the moments when these pieces were created as “defining moments in the bike.”

Other items like the fly screen, skid plate, crash bar and fenders are all custom pieces as well. He has garnered the attention of aftermarket companies as well, such as Ohlins which builds a custom spec rear shock and fork for the SC3 Adventure. Carducci estimates he now works with 10 companies which provide different pieces for the bike, from LeoVince for the exhaust canister, Corbin for the custom seat and Melvin USA for brake lines.

In all, Carducci estimates that about half of the SC3 Adventure is built from parts he’s designed while most of the rest come from aftermarket companies. Pieces which remain from the original Sportster are the lightly modified frame, engine, rear brake caliper and rotor, master cylinder and axel, instrumentation, oil tank, wire harness and handlebar switches.

In keeping with his profession, once the prototype was completed Carducci ran structural analysis and computational fluid dynamics tests to ensure the machine was properly built. He paid special attention to airflow over the bike, as the high front fender blocked much of the air needed to cool the engine. After conducting a number of tests he decided to cut slots in the rear portion of the front fender to optimize airflow.

“It’s been engineered to be lightweight, strong, safe and reliable,” says Carducci. “That’s key. Since I built it for myself I wanted to make sure I hadn’t done anything to myself, number one, and now that I’m trying to make it available to others I want to make sure it’s rock solid and safe.”

Carducci Dual Sport, as a business, is less than a year old at the writing of this article. Carducci and his wife have their headquarters in the same building as the machine shop which makes all the custom parts in Sunnyvale, California. They entertained the idea of selling the parts individually early on, but it proved cost prohibitive so decided to offer fully-built SC3 Adventures to buyers instead. They’re currently scaled to produce about six machines a year, and the going rate for a fully built SC3 Adventure is $72,000.

Initial response to the machine has been overwhelmingly positive though, and if there’s enough interest to allow for larger-scale parts manufacturing the price point should drop. Carducci has already taken steps in this direction through a partnership with IMS, who now produce a plastic tank option for the SC3.

As for Harley’s reaction, Carducci says he’s had two interactions with representatives of the brand.

“One is our local Harley dealer, and I took it there and those guys were all over it. They thought it was fantastic. And the second was at the San Mateo IMS Show where we won the J&P Ultimate Biker Build Off in the MOD Harley Class. That was really cool. It was accepted among the custom bike builders because its peer voting. Harley sponsored it, so I talked to one of their executives about it but they were pretty tight lipped and didn’t say much about the finished product. Just said ‘very good job’ and that’s about it.”

In terms of a ride, Carducci explains that for him, the SC3 falls somewhere between the performance of a KTM 950 and 990 in terms of off-road capability.

“I ride the bike pretty hard off road in our local parks here and it handles surprisingly well and the traction is really good too, the way it hooks up.”

Dry weight is a claimed 475 pounds, which puts it near the weight of KTM’s 1190 Adventure and BMW’s F800GS.

When asked whether he saw something lacking in the current dual sport/adventure market, Carducci explains that the SC3 was a way of getting back to basics while still retaining an engine he loved.

“I was watching these dual sports evolve and it seemed they were tending to go more street, more plastic, more things, more gadgets which is fine –it’s great to have all that stuff but I always wanted something a little more off road, a little more elemental. Plus I wanted this nostalgic V-Twin motor, which I’ve always liked. It’s something different and unique out there.”

Carducci Dual Sport SC3 Adventure 

Jim Carducci  founder of Carducci Dual Sport and designer of the custom pieces found on the SC3 Adventure  putting the bike through its paces off road. The fly screen of the SC3 Adventure is another piece designed by Carducci specifically for the bike. Through a partnership with IMS  Carducci Dual Sport also offers a five-gallon plastic gas tank option instead of the hand-forged aluminum piece.
Corbin makes a custom seat for the SC3 Adventure. Initial response to the SC3 Adventure has been overwhelmingly positive. Rear rack on the Carducci Dual Sport SC3 Adventure.

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