Custom Harley Parts Manufacturer

Core Manufacturing Technologies: Engineering for Heritage & Performance

1. Precision CNC Machining for Engine & Drivetrain

• V-twin engine components: CNC mills aluminum cylinder heads and timing covers with 0.02mm surface flatness, replicating 1960s Panhead/Shovelhead profiles while adding modern oiling channels. A custom Evo engine cam cover with integrated breather ports reduced oil leaks by 70% vs. stock, maintaining authentic 1984-1999 styling.
• Transmission parts: Machines 4140 steel shift forks and gear shafts with ±0.01mm tolerance, ensuring smooth engagement (≤0.5mm play) in 5-speed/6-speed transmissions. A 1970s Shovelhead transmission rebuild kit with CNC-machined components reduced gear noise by 25% during 10,000km testing.
• Belt drive components: Turns aluminum pulley hubs with 0.005mm concentricity, paired with carbon fiber-reinforced belts (20% stronger than stock) for 50,000+ km service life. A custom Softail pulley with 1.5-inch wider offset maintained belt alignment at 120km/h, eliminating premature wear.

2. Hand-Formed Body & Chassis Parts

• Steel fender shaping: Uses English wheel and power hammer to form 16-gauge (1.6mm) cold-rolled steel fenders, achieving 1950s-style rolled edges and 2mm radius curves. A 1948 Panhead front fender with 3-inch stretch maintained 0.5mm uniform thickness, with hand-finished welds polished to invisible seams.
• Aluminum gas tanks: Spins 5052 aluminum tank shells (0.8mm thickness) on CNC lathes, then hand-welds baffles and fittings—creating 3.8L-18.9L capacity tanks with 100% leak testing (0.1cc/min max seepage). A custom Sportster tank with 4-inch stretch and 2-degree rake fit perfectly with OEM frame mounts (±0.5mm gap).
• Handlebar bending: Heat-treats 4130 chromoly steel bars (25.4mm-32mm diameter) to 30-35 HRC, then precision bends to custom rise (8-16 inches) and pullback (4-12 inches) with ±1° angular tolerance. A 12-inch Ape Hanger handlebar maintained 100MPa yield strength, withstanding 10,000+ vibration cycles at 3,000 RPM.

3. Performance Exhaust Systems

• Stainless steel exhaust fabrication: TIG-welds 304 stainless steel tubes (1.5-2.5-inch diameter) with mandrel bends (radius 3× diameter) for 15% better flow than stock. A Twin Cam exhaust with 2-1 merge collector increased horsepower by 8hp at 5,000 RPM, verified on dyno testing.
• Ceramic coating: Applies 0.05mm thermal barrier coating (black, silver, or custom colors) to exhaust headers, reducing under-tank temperatures by 50℃ and withstanding 650℃ continuous heat (ΔE <2 after 500 hours).
• Vintage exhaust replication: Uses 1940s-1960s blueprints to recreate cast iron mufflers and heat shields for Knucklehead/Flathead restorations, with 98% dimensional accuracy to original parts.

4. Finishing & Authenticity Preservation

• Chrome plating: Triple-plates (copper/nickel/chrome) on steel parts (0.05mm total thickness) for mirror finish (Ra ≤0.02μm) and 1,000+ hours salt spray resistance. A 1957 FL front fork slider set achieved show-quality chrome, with 95% coverage of complex recesses.
• Powder coating for durability: Applies textured or gloss powder (60-80μm thickness) to aluminum/steel parts, matching Harley’s factory colors (Vivid Black, Candy Apple Red) with ΔE <1. A custom Dyna rear fender with wrinkle-black finish maintained texture consistency across 500 units.
• Patina finishes for vintage style: Creates controlled rust or oil-rubbed finishes on steel parts (e.g., gas tank straps, brackets) to replicate 50-year-old patina, sealed with clear coat to prevent further corrosion.

Material Expertise: Matching Materials to Harley Part Requirements

 

Custom Harley Parts Manufacturing Process

1. Design & Authenticity Validation: Engineers work with clients to:
   • Match vintage specs (e.g., 1965 Electra Glide tank dimensions with 3.8L capacity)
   • Enhance modern performance (adding oil passages to Shovelhead rocker boxes)
   • Ensure fit with OEM or custom frames (±0.5mm tolerance for bolt holes)
     Using 3D scanning of original parts (0.05mm accuracy) for restorations.
2. Prototyping:
   • CNC machined aluminum/steel prototypes for fit testing
   • Hand-formed clay models for gas tank/fender contours
   • Test fitting on client’s bike (with photos for approval)
3. Production:
   • Hand-forming (steel/aluminum) for body parts
   • CNC machining for engine/transmission components
   • TIG/MIG welding (with invisible seam finishing for show parts)
4. Finishing:
   • Polishing (Ra 0.02μm for chrome prep)
   • Plating/powder coating per finish specs
   • Assembly of hardware (chrome bolts, stainless steel fasteners)
5. Quality validation:
   • Fit testing on OEM frames (Harley-Davidson-approved jigs)
   • Vibration testing (3,000 RPM for 100 hours)
   • Leak testing (gas tanks: 3 psi air pressure for 24 hours)

Custom Harley Parts Application Fields

• Vintage Restorations: 1936-1969 Knucklehead/Flathead/Shovelhead parts (gas tanks, fenders, engine covers) with authentic materials and finishes.
• Custom Builds: One-off parts for bobbers, choppers, and baggers (stretched gas tanks, 21-inch front fenders, custom handlebars).
• Performance Upgrades: High-flow exhausts, lightweight aluminum engine covers, and reinforced transmission parts for increased horsepower/torque.
• Accessories: Chrome trim, leather-wrapped handlebars, and custom grips that blend vintage style with modern comfort.

Customization Capabilities: From Classic to Radical

 

• Vintage authenticity:
  • Correct metal gauges (16-gauge steel for 1950s fenders)
  • Factory-style welds (stacked dime pattern for 1960s frames)
  • OEM color matching (1950s Harley Orange, 1970s Candy Blue)
• Performance enhancements:
  • Lightweight aluminum (saves 5-10kg vs. steel parts)
  • High-flow exhaust designs (dyno-proven gains)
  • Reinforced components (transmission gears, shift forks)
• Custom styling options:
  • Tank stretches (2-6 inches) and rake angles (1-5 degrees)
  • Handlebar rise/pullback combinations (8-20 inch rise)
  • One-off engraving (tank badges, derby covers with custom logos)

Common Customization Questions

• Q: Can you replicate NOS (New Old Stock) parts that are no longer available?
  A: Yes—3D scanning of rare NOS parts (e.g., 1948 Panhead rocker boxes) creates digital models, then we machine/reform using original materials (cast iron, 1018 steel) to achieve 99% accuracy.
• Q: What’s the lead time for a custom 2.5-inch stretched gas tank?
  A: 7 days for design/fitment, 14 days for hand-forming, 10 days for finishing—total 31 days. Rush options for show builds cut lead time by 40% with priority workshop time.
• Q: Will custom exhausts fit with my existing engine guards or saddlebags?
  A: Yes—we 3D scan your bike’s existing accessories (engine guards, bags) to design exhausts with 10mm+ clearance, verified via test fitting on a duplicate frame.
• Q: How to ensure powder coating matches Harley’s factory colors?
  A: We use Harley-Davidson-approved powder suppliers and spectrophotometers to measure color (ΔE <1), with a physical sample sent for client approval before full production.

Ready to Build Your Dream Harley?