I bought the donor 2003 H-D 883 Sportster on December 31, 2010. On the next day, January 1st 2011, I began tearing it apart and started the reverse engineering process. I measured the parts I would keep and design around, like the engine, frame and a few others. The unneeded parts were donated to a moto club co-op in San Francisco, CA.
Six months later I had a rolling prototype, the SC3 Adventure, which consisted of the Sportster motor and the frame with some minor mods, a custom designed billet Aluminum swingarm, a KTM 525 front end, a small tracker gas tank, 18” rear wheel and 21” front wheel both with knobby tires, and a hand modified seat that looked pretty bad. The bike worked well, proving the concept and geometry.
I spent the first few months on the CAD system laying out the 2-D architecture side-view before designing and machining any parts. I nailed down the critical geometry: wheel base, rake, trail, rider position, foot controls and handlebar position, and instantaneous force center related to swingarm length and angle. All are key to the bike performing well on road and off.
Once the architecture was set, I began design engineering the components in 3D CAD solid modeling. I quickly had a complete solid model assembly of the entire bike along with fully documented detail drawings of every part and a complete Bill of Materials (BOM) down to the last nut, bolt, and washer.
The bike evolved over the next three years, consisting of refining and adding features like improved suspension, a larger gas tank for longer range, a better seat, a lighter and higher performance exhaust, better brakes, repositioned foot controls, a wind screen, hand guards, and a few other more minor details.
My goal was to build the best performing adventure dual sport around the H-D Sportster motor, and fully document it to be reproducible to spec. I accomplished my goal and have proven the reproducibility by building a second SC3 Adventure thru a controlled build. I bought another donor Sportster, ordered all the parts from our drawings and BOM, and then assembled the bike to spec. The entire process took only four months start to finish.
Now that both bikes are done, I’m riding them as much as I can, both on the road and in the dirt. On the asphalt, the SC3 Adventure handles the twisties well. It’s a neutral steering bike turning effortlessly and at high speeds is inherently stable. Off road in the dirt, the SC3 Adventure is confidence inspiring and loves the open desert and sand washes where high speeds are not a problem and the bike is very stable. Watch for our MotoGEO video to come out soon where Jamie Robinson pushes the SC3 Adventure’s limits in the Mojave Desert.
All my riding experiences to date have been positive and I’m having a blasting through many miles and showing it at motorcycle shows or during rides. The SC3 Adventure grabs a lot of attention everywhere I ride. The only negatives have been not being able to ride it as much as I want. A short-term voltage regulator grounding problem drained the battery and stranded me a few times until I solved the problem.
Now both bikes are finished, I have more time to go riding, so life is good, and my wife rides one of them
One of the most asked questions I get is, “Why did I design and build it?” I have a background in engineering disruptive technologies. I’ve been riding Harleys and adventure dual sports for as long as I can remember, and I wanted to combine the two.
I would ask myself and my friends and anyone else who would listen, “Why isn’t there a good American adventure dual sport?” And, “Will H-D make one?”
With my background and experience I knew I could build a good one based on the solid-mount Sportster chassis model years 1993 to 2003. Since the words “H-D” and “Dual Sport” are rarely spoken in the same sentence, once again I was engineering a disruptive product. I knew it would be a controversial build as it has proven to be. Some love it, some hate it, buyt it always draws plenty of extreme comments.
What’s next? A few things: Now that the SC3 Adventure design is complete and fully documented and patented, it is turn-key ready to be produced in volume. We are looking for a manufacturer to license the design and produce the SC3 Adventure parts, kits, and/or complete bikes, and make them available to purchase.
Following that, we will stick to our core competency of design engineering and prototyping of custom adventure dual sport motorcycles. We are moving on to the next adventure dual sport design … stay tuned for details!
The background story on why I designed and built the SC3 Adventure:
When I was 10 years old, my father’s friend gave me my first ride on a motorcycle – a Honda CB750. I sat in front of him on the gas tank, no helmet, and held on to the center of the handlebars for dear life. We rode on the freeway at a pretty high speed – at least it felt fast to me – and I was hooked from then on.
The next year my mom bought me my first bike, a new 1974 Honda XR75. I’ll never forget it. I immediately took that bike apart all the way down to the frame just to see how it was made, then rebuilt it. That bike unfortunately was stolen in a house break-in and eventually the thief was caught – which led to my second bike.
The thief’s parents paid for the replacement cost of the bike since the bike was trashed. We put that money towards a new 1975 Yamaha DT100 – my first street legal dual sport. I didn’t have a driver’s license at the time, but I would ride it thru our neighborhood streets to get to local dirt areas to ride. Soon I ripped all the dual sport lights off the bike, added a plastic gas tank, and made it more off-road capable. That is when I started customizing motorcycles.
My third bike was a new 1977 Yamaha YZ125, which I started racing motocross at our local PAL (Police Athletic League) track. I raced it for a few years and made mods to the suspension and motor myself by making parts in my parent’s garage and buying motor parts with my allowance.
Back in the day, we didn’t have the internet, so I found parts from magazines and then bought them from our local motorcycle shops or thru the mail. The racing ended when I turned 15-1/2 years old and bought a 1978 Yamaha RD400 street bike. The serious customizations started when I transformed that into a café racer by doing mods and bolting on custom parts.
From that time on, I’ve had many bikes over the years and I’ve always liked Harleys for as long as I can remember. I’ve had a number of them, including a Buell X1. I’ve also been dual sport riding since I was a kid. As long as I can remember, I’ve wanted a Harley that was dual sport capable. Years ago, Harley made a dirt bike and also a 2-stroke dual sport, but I wanted to see their real Harley, maybe a Sportster turned into a dual sport. As a California kid, I remember watching the TV series, “Then Came Bronson,” where actor Michael Parks rode a Sportster around California. Parks was always riding it off-road when he could. I think that’s where the obsession of wanting to make my own Harley Sportster dual sport began, and also my desire to do rides like he did: Adventure Dual Sport riding.
Owner: Jim Carducci
Bike Name: Carducci Dual Sport SC3 Adventure
City/State: Sunnyvale, CA
Builder: Jim Carducci
City/state: Sunnyvale, CA
Company Info: Carducci Dual Sport LLC (CDS)
Address: 141 S Taaffe, #70312
Sunnyvale, CA 94086
Phone:
Web site: www.carduccidualsport.com
E-mail: jim@carduccidualsport.com
Design: Jim Carducci
Fabrication: CDS, Evan Wilcox, Curt Winter of BTRmoto, Corbin seat.
Manufacturing: CDS
Machining: LUX Manufacturing for all CNC parts
Year: 2003, Donor H-D 883 Sportster
Make: H-D
Model: 883 Sportster
Displacement:1250cc with NRHS kit
Builder or Rebuilder: Jim Carducci
Cases: OEM
Case finish: OEM
Barrels: NRHS 1250cc
Bore: NRHS 1250cc
Pistons: NRHS 1250cc
Barrel finish: Black exterior
Lower end: OEM
Stroke: OEM
Rods: OEM
Heads: OEM 883 Sportster
Head finish: OEM
Valves and springs: OEM
Pushrods: OEM
Cams: Andrews N4
Lifters: OEM
Carburetion: OEM CV carb rejetted
Air cleaner: K&N with ASB carbon fiber cover
Exhaust: BTRmoto 2 into 1 custom header
Mufflers: Leo Vince muffler with spark arrestor
Transmission
Year: 2003 H-D 883 Sportster
Make: H-D
Gear configuration: OEM 5-speed
Primary: OEM chain
Clutch: OEM with Mueller lever arm for light clutch pull
Final drive: RK Racing 530 o-ring chain conversion, 25/56 teeth front/rear sprockets
Frame
Year: 2003
Builder: H-D frame modified by Jim Carducci
Style or Model: OEM Sportster
Stretch: 62.5”wheel base. Swingarm extended 4”
Rake: 27 degrees
Modifications: Minor mods – some brackets removed. Added support gussets at swingarm pivots, steering damper post bracket, and gas tank mount
Front End
Make: Ohlins
Model: Offroad MX
Year: 2014
Length: Length reduced 2.5” inches for 9” travel. Stiffer springs
Risers: CDS custom designed – CNC machined billet Aluminum includes elastomer vibration dampers, height adjustment, and front/rear adjustment to accommodate rider preference.
Sheet metal
Tanks: Evan Wilcox hand formed Aluminum 6.3 gallon. I did the design, then CNC machined it out of Styrofoam for a test fit and plug for Evan to measure and make his patterns from.
Fenders: Rear – Aluminum fender subframe & utility rack including support for two 1/2 gallon gas containers. Front – plastic KTM fender.
Panels: Removed. Minimal design for weight reduction.
Oil tank: OEM
Other: Aluminum skid plate, fly screen, voltage regulator guard.
Paint: Old School Customs (OSC) Ron McRae.
Paint
Molding: 5.0 gallon IMS XLPE plastic gas tank offroad option is rotational molded; co-developed with IMS Products, Riverside, CA.
Base coat: Powder coated frame
Graphics: Designed by Brandon Rike, painted by Ron McRae of OSC
Frame Base coat: Powdercoated
Graphics or art: Rear fender and swingarm logos designed by Brandon Rike
Pinstriping: OSC Ron McRae on gas tank
Wheels
Front: Woodys Wheel Works
Make: Custom build – Excel rim, Rad hub, heavy gauge SST spokes
Size: 21” x 1.85” wide
Brake calipers: Beringer 6-piston radial caliper modified for bigger custom CDS rotor, CDS radial-to-axial adapter bracket
Brake rotor(s): 1x 380mm diameter floating custom designed and fabricated by CDS
Tire: Continental TKC80 90/90-21
Rear: Woodys Wheel Works
Make: Custom build – Excel rim, Billet Boys hub, heavy gauge SST spokes
Size: 18” x 3.5” wide
Brake calipers: Beringer 4-piston caliper & mounting bracket
Brake rotor: Beringer 291mm diameter floating
Pulley: N/A – 56 tooth chain sprocket
Tire: Continental TKC80 140/80-18
Controls
Foot controls: CDS custom design billet Aluminum shifter, brake, foot pegs, supports.
Finish: Anodized
Master cylinder: Beringer
Brake lines: Melvin custom SST braided per CDS specs
Handlebar controls: OEM H-D throttle and electronics, Beringer front brake and clutch levers.
Finish: Anodized
Clutch Cable: OEM
Brake Lines: Melvin custom SST braided per CDS specs
Shifting: CDS billet Aluminum machined linkage and shift lever.
Kickstand: CDS designed and fabricated chrome moly tubing with Aluminum adapter bracket to OEM H-D Sportster frame mount.
Electrical
Ignition: OEM
Ignition switch: OEM
Coils: OEM, relocated to side of motor for better access and cooling
Regulator: OEM
Charging: OEM
Starter: OEM
Wiring: OEM with minor mods for LED blinkers / tail light.
Harness: OEM
Headlight: Trail Tech 55watt halogen Baja flood light
Taillight: Acerbis LED
Accessory lights: None
Electrical accessories: Badlands electronic turn signal module for LED lights
Switches: OEM
Battery: Shorai Lithium-Ion. 10 lbs weight reduction
What’s Left
Seat: Custom Corbin hand formed to frame and gas tank
Mirror(s): DRC 161 off-road mirrors, adjustable height
Gas caps: No-Toil billet Aluminum, internal vented.
Handlebars: Biltwell 1” chrome moly tracker bars
Grips: Biltwell Thruster grips 1” diameter
Pegs: Pivot Pegz
Oil filter: Pure Power SST screen pass thru oil filter
Oil cooler: None
Oil lines: OEM
Fuel filter: OEM
Fuel Lines: OEM
Throttle: OEM
Throttle cables: OEM
Fasteners: All SST and nylock nuts
Specialty items:
Swingarm: Billet Aluminum CNC machined truss structure for light weight and stiffness, extended 4”
Rear Shocks: Ohlins twin shocks, 8”+ travel at rear axel.
Foot Controls: Billet Aluminum CNC machined mounting brackets and levers.
Triple Clamps: Billet Aluminum CNC machined top & bottom, bar risers with vibration isolation, height and front/rear adjustment.
Steering Damper: Integrated Scotts damper with post mount welded to frame.
Credits:
Evan Wilcox – hand formed Aluminum gas tank
IMS – XLPE plastic gas tank
Curt Winter, BTRmoto – Hand welded exhaust header
LUX manufacturing – CNC machining
Corbin – Handmade seat
Graphics – Brandon Rike
Paint – Ron McRae, Old School Customs
