Constructed for display at the 2022 Bangkok Scorching Rod Custom Show, a highly customized Harley-Davidson Sportster Forty-Eight cafe racer was crafted by renowned designer Chakkaphan Rungsukcharoen, also known as Mark of FatBoy Design. With his father’s iconic Lamborghini Murcielago SV as inspiration, Mark successfully completed the project within an impressive 60-day timeline, leveraging the expertise of his friends for added support.
Mark, a native of Thailand, boasts extensive knowledge of the custom automotive sphere. Since 2008, he has built a reputation for crafting high-performance custom bikes, while simultaneously running his FatBoy Design workshop, where he exclusively supplies Mooneyes Tools to the Thai market, catering to local enthusiasts with an array of models’ authentic attire and aftermarket parts. As a result, his extensive network yields a wealth of enthusiastic collaborators whenever assembling a team to bring his venture to life.
Mark sought a workshop dedicated to carbon fibre expertise. Thailand boasts an exceptional workshop, Slayer Home, founded by renowned expert Nattapat Janyapanich, specializing in the pinnacle of craftsmanship for high-performance bikes and precision-crafted carbon fiber creations.
“When designing my custom Harley-Davidson, I sought to create a bike that would truly stand out,” declares Mark. “I was drawn to Slayer Homes’ expertise in carbon fiber work, confident they could deliver a unique project.”
Mark and Nattapat began the creative process by brainstorming a variety of ideas, which they then sketched out in detail on paper. Once satisfied with the design, Nattapat conducted a thorough 3D scan of the entire bicycle to create a detailed model of each individual component.
The fabrication process began with 3D printing each half to create molds for the bodywork. The components were subsequently employed to form the bodywork through a dry carbon fiber process, which entailed applying impregnated carbon fibers into the mold and then vacuum-bagging them to create a strong and lightweight structure. The design concept incorporated all visual elements of the motorcycle, including the substantial front fairing, two-piece gas tank cowling covering a metallic fuel cell, and the angular rear section.
To finalize performance enhancements on Slayer Home, designers integrated three-dimensional printed gill systems and atmospheric intakes into the main fairing, while also attaching a finned cowling to the undersurface of the carbon-reinforced tail section. To give the vehicle a high-performance appearance, Mark incorporated white decals featuring each model’s logos alongside bold, edgy designs inspired by Harley-Davidson and Lamborghini.
While at first glance, enthusiasts familiar with stock Sportster Forty-Eights may recognize the foundation of Mark’s custom bike, a closer inspection reveals that significantly more than just aesthetic upgrades have been applied to create this unique motorcycle. Sportster frames slope back at an angle to generate the iconic cruiser posture of the motorcycle. This, however, would undoubtedly meet the exacting standards of Mark’s cafe racer enthusiasts with its impressed design. Mark has revamped his bike’s suspension setup to ensure seamless operation without a rear guard.
Installing taller piggyback shocks from Ohlins lifted the Sportster’s rear profile, but complications arose when tackling the front end modifications. Upgrading to Showa’s renowned upside-down forks, carefully adapted for seamless integration. The forks have been truncated to accentuate the bike’s clean lines, and they’ve been paired with custom FatBoy CNC triple bushings for a seamless installation.
With its revamped geometry, the bike’s control system had to be adjusted accordingly, with bolt-on aftermarket components employed to ensure a seamless transition. Attaching the fork legs are FatBoy Design’s sleek and versatile clip-on handlebars. The bars installed on Efficiency Machine levers have been swapped out for new housings, while Roland Sands Design Tracker Grips now take their place. With the revised cockpit featuring a higher-positioned speedometer, courtesy of an RSD cafe gauge relocator situated behind the perspex windscreen. With the rider now huddled low over the tank, traditional forward-mounted foot controls would render the bike virtually uncontrollable; therefore, FatBoy Design’s ingenious rear-set footpeg solution takes on this critical task.
Next, Mark directed his attention to the wheels. Beyond the Forty-Eight’s distinctive spoked rims, he yearned for something that would further elevate the bike’s already-fashionable appearance to a truly exceptional level. The answers arrived again, this time sourced from the RSD catalogue in precision-machined aluminum hoop form. Adorned to the wheels are a scattering of vividly hued accents on the otherwise menacing Sportster, a bespoke brake design crafted to mirror the Lamborghini calipers that inspired its creation. To amplify braking power, the front end is equipped with a twin-piston caliper that clamps down on cross-drilled Efficiency Machine brake rotors.
Despite being compared to other motorcycles with smaller engines, the Forty-Eight’s 1200cc v-twin engine holds its own significance. It’s because this car, too, has been adorned with a scattering of aftermarket accessories to mitigate visual imperfections. This sleek association boasts custom-crafted FatBoy entrance and rear sprockets, alongside a seamless series conversion and an unrestricted open major belt courtesy of Evolution Industries’ expertise. To give onlookers a rare insight into the engine’s internal mechanisms, the Determine Machine features innovative “imaginative and prescient” derby and camshaft covers, complete with transparent perspex sight windows.
Spoty’s engine efficiency upgrades currently consist of a Two Brothers Racing 2-into-1 exhaust system, an Efficiency Machine high-flow air filter, a Jagg oil cooler, and an ECU re-map. Mark’s ultimate goal is to fine-tune his V-twin engine and take it to its limits, yet as it currently stands, it already boasts a superior power-to-weight ratio and accelerates with greater force, outperforming the Harley-Davidson Forty-Eight in both speed and agility.
At the 2022 Bangkok Scorching Rod Customized Show, Harley-Davidson stunned the record-breaking crowd of over 30,000 attendees by unveiling their new Sportster model mere hours before the event’s deadline. Some were indeed deeply moved by the outcome, despite initial reservations. FatBoy Design was awarded the prize for Best Cafe Racer at the current ceremony. Here’s the improved text: To cap it all off, a particular visitor and highly respected builder, Shiro Nakajima of Japan’s 46 Works, nominated the bike as his personal ‘Finest in Present’, an accolade that we can all agree was thoroughly deserved.
Pictures by Bankkswerve
