The Buell S1 1998 “Thunderstorm” by Speed of Color is a radical reinterpretation of one of the most raw and characterful American naked bikes ever built.
Known for its aggressive stance and torque-rich V-twin, the Buell S1 becomes something truly special in the hands of Speed of Color (SOC)—a machine that blends performance engineering, high-end materials, and unmistakable custom design.
At the heart of this build is a fully rebuilt engine featuring the legendary “Thunderstorm” cylinder head upgrade, significantly improving airflow and power delivery. Performance is further enhanced with a Mikuni HSR 42 carburetor conversion, paired with a Forcefinder air filter and a dedicated engine breather kit, ensuring crisp throttle response and optimal engine breathing. The sound and attitude are delivered through a race-spec carbon exhaust silencer, perfectly matching the bike’s aggressive nature.
Power is transferred to the ground through a heavily revised drivetrain. The original rear rim has been widened to 6.25 x 17 inches, allowing for a massive 200/50 ZR17 Metzeler Sportec M3 rear tire, while the front runs a 120/70 ZR17 Metzeler Sportec M3, offering excellent grip and balance. A 6 mm offset drive sprocket with a CNC-milled one-off cover ensures proper alignment, while the revised original pulley wheel maintains reliability with improved performance.
The chassis and suspension setup reflect a clear focus on handling precision. The bike features a Metmachex aluminum swingarm, combined with a fully adjustable AST rear shock absorber offering independent high- and low-speed compression adjustment as well as rebound damping. At the front, the forks are upgraded with DLC-coated slider tubes, anodized fork tubes, and progressive AST springs, all held together by a custom RRC fork bridge with triple clamping below and double clamping above, allowing adjustable wheel trail for fine-tuned handling.
Braking performance has been significantly upgraded to match the bike’s power. The front end now runs a double disc conversion with Braking Wave discs, while the rear also features a Braking Wave disc paired with a 4-piston brake system. Steel braided lines, SM brakes, and PAZZO brake and clutch levers provide excellent feel and control under aggressive riding conditions.
The rear section is unmistakably SOC. A Speed of Color rear part with an integrated double rear light in “shark nose” design gives the bike a sharp and futuristic look. This is paired with a custom SOC leather seat featuring a laser-engraved motif, blending craftsmanship with modern detailing. The riding position is completed by LSL rear controls, an LSL Fatbar handlebar (28.5 mm), and discreet Kellermann handlebar-end indicators at the front.
Visually, the bike stands out through its extensive use of premium finishes and materials. The paintwork by Speed of Color is complemented by real carbon fiber elements on the fuel tank, rocker box rings, inspection covers, and oil tank. The frame, rims, and swingarm are specially coated, while the exhaust manifold and silencer are finished in black. Numerous components are powder-coated and laser-engraved, including details such as the SOC Pointcover, RRC pulley cover, and GSG brake reservoir.
The Buell S1 “Thunderstorm” by Speed of Color is not just a custom motorcycle—it is a high-performance, design-driven statement. It perfectly combines American V-twin muscle with German engineering precision and bespoke craftsmanship, resulting in a machine that is as thrilling to ride as it is to admire.
Buell parts
- Engine: “Thunderstorm” cylinder heads upgrade, engine rebuild
- Air filter: Forcefinder
- Exhaust / silencer: Race silencer carbon
- Carburettor: Conversion to Mikuni HSR 42 carburettor
- Engine breather: engine breather kit
- Rear wheel rim: Original rim widened to 6.25″ x 17″
- Pulley wheel: Original pulley revised
- Tyres: Metzeler Sportec M3 – front: 120 / 70 ZR 17, rear: 200 / 50 ZR 17
- Drive sprocket: 6mm offset sprocket with CNC-milled cover (one-off production)
- Rear part / seats: SOC rear part with integrated double rear light “shark nose”, SOC leather seat with laser motif
- Front fender: standard
- Cockpit: –
- Handlebar: LSL Fatbar handlebar 28.5mm
- Indicators: Front: Kellermann handlebar end indicators
- Mirror: –
- Fork: Fork tubes anodized/slider tubes DLC coated, progressive AST springs
- Fork bridge: RRC fork bridge with triple clamping below and double clamping above, custom-made with adjustable wheel trail
- Shock absorber: AST shock absorber 3-way adjustable (high / low speed compression & damping travel)
- Footpegs: LSL rear controls
- Brakes: Conversion to a double disc system at the front with Braking Wave discs and a 4-piston brake system at the rear, Braking Wave brake discs at the rear, SM brakes, steel flex lines, PAZZO brake and clutch levers
- Engine Spoiler: –
- Headlight: V-Rod headlight with custom V-Rod lamp holder
- Rear swing arm: Metmachex aluminum swing arm
- Pulley Cover: RRC Pulley Cover
- Extras: SOC Pointcover, GSG brake reservoir
- Paintwork/Coating: Paintwork by SOC; Tank, rocker box rings, inspection covers and oil tank covered with real carbon; Frame, rims and swingarm specially coated; Manifold and exhaust black coated; various parts powder-coated and laser-engraved.
