Carducci’s SC3

“The most challenging time I’ve had on the SC3 was a ride in Death Valley up to Cerro Gordo. I’d been there years ago on a different bike and made it to the top, but this time I was with a group of Adv riders that didn’t know the way. We ended up taking a gnarly jeep trail that resulted in a bunch of GS Adventures getting flipped upside down off the trail. At that point, we decided enough was enough and turned tail to go back. The SC3 did great on some of the most challenging terrain it has been ridden on. More than a few of the riders were surprised that a Harley could handle that kind of ground and do so well.” Jim Carducci is the co-founder of Carducci Dual Sport. “My wife Sherry is the other co-founder, and we live and work in Sunnyvale, CA, the heart of Silicon Valley.”

“My mom bought me my first bike, a new Honda XR75 dirt bike after she divorced my dad who wouldn’t allow me to have a motorcycle. I was eleven, and it’s a bittersweet memory.” But the day after he got it Jim tore it apart down to the ground and then rebuilt it “just to see how it was made”, but that was after riding it around the backyard and tearing up some of the lawn first. It’s no surprise then that Jim has been building motorcycles ever since. “At that age though, it was more finding parts I liked in magazines or local moto shops and buying them, well my Mom paid. Then making custom bracketry in our garage with basic tools like a hacksaw, tin snips, and a hammer. Good times! After high school, I decided to become a mechanical engineer and have been doing that professionally ever since in the aerospace and semiconductor industries. Today, I do semiconductor equipment design by day and build these custom motorcycles on nights and weekends.”

“Just about every motorcycle I’ve owned I’ve done some level of modification on.” After Jim became a mechanical engineer, he started using his engineering and CAD skills to design parts to have them made at local machine shops. “We have a lot of machine shops here in the Silicon Valley that produce very high quality fabricated parts from just about any material. Most of the parts on our SC3 Adventure were made at LUX Manufacturing, just a few minutes away from us.” Throughout the years Jim has ridden all types of motorcycles including racing motocross as a kid. “But today, I’m focused on, and truly love, the big adventure and dual sports bikes” So, with those interests and his experience and professional background, he decided to design and build a custom adventure motorcycle based on the Harley Davidson Sportster. “This started back in 2011, and the motorcycle has evolved into our latest build of the SC3 Adventure.”

“I love the look, the exhaust sounds, and the torque of the Sportster motor. Was it the best motor choice for an adventure dual sport? Maybe not, but that’s not what this build was about. It was about a motor that I’ve loved since watching “Then Came Bronson” on TV as a kid. In the series, Michael Parks rode a Sportster around the California back roads and occasionally ended up off-road.” And from this stems his drive for taking the HD platform off the beaten path. “The SC3 Adventure has turned out much better than I originally expected. It handles surprisingly good in the dirt for a big bike. The motor is very narrow, so when you sit on it, it looks like a smaller bike. For traction off-road, there’s something about the single pin crank and firing order of the Sportster motor that provides a good traction hook-up in the loose dirt. One of the reasons I think the H-D XR750’s did very well in flat track racing for years.”

The build process starts with a 2D CAD model side view of the motorcycle to work out the overall architecture, geometry, suspension travel, and ergonomics. “Once that is done, I start 3D CAD modeling new parts to be made, doing FEA structural analysis as needed for safety and reliability, and spec’ing out the aftermarket parts.” Then he makes a complete CAD solid modeled virtual assembly of the motorcycle, down to every nut, bolt, and cable. “I use the model for visualization, rendering, and fit checks of components before having the individual parts made. Virtual checks like this save tons of money and time and prevent embarrassing fit issues.” All this happens before he ever touches a real part. “It’s hard to resist jumping right into cutting metal, but I’ve learned over the years that spending more time up front in design and engineering usually yields a better product and in a shorter amount of time.”

Another reason Jim chose the 2003 Sportster’s engine and frame is due to the geometry being suitable for an adventure dual sports bike. With the suspension components modified, it would be strong enough to handle off-road riding. “2003 was the last year of the hard mount motor with Harley switching to rubber mounts with heavier motors the following year. I didn’t feel it would be good for off-road use to lose the feel of the motor. To get the geometry dialed in, I lengthened the swingarm and increased the rear wheel travel which pitched the frame forward pulling in the rake and increasing the trail.” The upside down front suspension and dual rear shocks are from Ohlins. Jim opted for an 18” / 21” wheel combo build by Woody’s Wheel Works with Excel rims and the heavy gauge stainless steel spokes the Denver based masters of wheel building have become famous for. The wheels are in turn stopped by Beringer brakes with a six-piston caliper up front and a four-piston caliper in the rear. Melvin brake lines supply the pressure.

While the Sportster throttle, speedometer, and wiring harness are stock, the front end got upgraded with Cycra Probend hand guards and adjustable handlebar risers that is vibration damped. “The fly screen frame is made of structurally strong sheet aluminum and supports a tinted polycarbonate wind deflector that reduces wind on the body.” A set of Baja Designs Squadron Pro lights with Skene high beam dimmer switch provides 9800 lumens while the LED brake light and blinkers were made to handle the vibrations of off-road riding. The seat is by Corbin and designed to be narrow in the front for a comfortable standing position while wider in the rear to make those miles seated more comfortable. Pivot Pegz were also fitted to provide the rider with better foot grip and load distribution while riding. “They help with body positioning enabling you to transfer body weight more easily, which in return, provides better traction.” The engine, in turn, has seen an NRHS 1250cc kit upgrade with Andrews N4 cams and an ASB carbon fiber cover. The carburetor was re-jetted and now breaths through a K&N high-flow air filter.

“Some of the key components we design and build are the swingarm, triple clamps, bar risers, foot controls, headlight assembly, crash bar, skid plate, kickstand, and rear fender and rack. They’re all CAD designed, CNC machined or fabricated out of high strength Aluminum.” The swingarm and triple clamps were the most demanding in design in that they are the key structural elements connecting the frame to the suspension and wheels. “They needed to be strong, stiff, and light, so I chose a truss structure design to achieve this, which lines up the neutral axis of the web elements to minimize bending moments leading to high stresses.” Something Jim was taught by an old bridge designer years ago. “We outsourced other key components like the 6 gal / 22.7 L hand formed aluminum gas tank made by Evan Wilcox which is a work of art. We did the tank CAD design to get the shape and volume right and shaped a full-size prototype out of Styrofoam to test fit on the bike. Evan took it from there and did his magic. Curt Winter of BTR Moto did the exhaust, and it is another work of art because of Curt’s welding, it is the best I’ve seen.”

The SC3 Adv has two canisters on the rear rack that can hold about a gallon of fuel total, but with the Aluminum gas tank, the range is in the 200 mi / 320 km plus arena. To reduce weight and make the bike more off-road capable Jim has also developed an XLPE plastic 5 gal / 19 l tank with IMS Products. “The result is a slimmer tank that weighs 3 lbs less than the aluminum version. We have a build in the works that will use this tank for an even more hardcore off-road application.” For years Jim has been a fan of running Continental TKC80’s on all his adventure or dual sports motorcycle. “They work equally well on road and dirt for me, but tread wear could be better. Recently I’ve been running the Mitas E-10’s and am liking them. They are big chunky, aggressive knobbys. Good on the off-road and the tread is lasting longer. So far, so good, and I must admit I am enjoying them.”

I love desert riding. I try to take the SC3 Adv into the desert as much as possible. I’ve ridden in Mojave many times, Death Valley, Anza Borrego, Carrizo Plains, the Eastern Sierras out of Minden and Virginia City. Much of the testing of the SC3 has been in local places like Hollister Hills SVRA off-road park which has plenty of challenging terrain. For testing and riding on the asphalt, we also have some of best twisty mountain roads around like Highway 9, Skyline Blvd, Alpine Road, Tunitas Creek, White House Canyon. I could go on and on … plenty to explore around here.” Riding a bike he built himself has its moments. One very magical moment came in the Mojave desert after a long, hard and hot day riding off-road for a 2015 Klim catalog photo shoot. “At the end of the day we were still chasing the light for the best photography, and we were up on top of a small mountain with one of the most striking sunsets I’ve ever seen. The colors were phenomenal purples, oranges, and yellows all blended in a desert haze. I stopped and watched the sunset while they were still trying to take pictures.”

When it comes to ADV motorcycling, Jim tends to keep it simple. “I always choose a motorcycle that is reliable and capable of the terrain, both on and off-road, that I’ll be covering while I make a point of not over packing to keep things as light as possible. The SC3 is a very minimal and elemental motorcycle with not too much that can break or fail and the bike is pretty easy to repair on the road.” I also like to ride with other riders. If you get hurt or stranded in a remote area, as I have, it may save your life!

“I thought to ride thru Mexico was going to be harder than it was due to not knowing the language and having to navigate thru remote places. The locals were very friendly, even curious about motorcyclists, and liked talking to us as we rode thru the small towns. We had navigation challenges, but the locals were always happy to help us get where we were trying to go. We rode a 2000 mi / 3220 km route down the length of Baja both on and off the road to La Paz. Took a ferry over to Los Mochis on the mainland and rode thru Copper Canyon down to Batopilas, and then up to the town of Creel. Definitely one of the best trips I’ve ever been on anywhere, and it was even better because it was on two wheels!”

The next evolution for the SC3 is top secret at the moment, but hopefully Jim and Sherry will be releasing the details soon. “Expect an even more off-road capable SC3 Adv. Exciting stuff!”

For more info and future updates follow Carducci Dual Sport on their Instagram account.

Images by Drew Ruiz for Klim, Alfonse ‘Fonzie’ Palaima, and Sherry Cordova for Carducci Dual Sport.