Product Description

Upgrade your BIGROCK RS crank system with the S-PARTS Titanium Crank Bolt & Self-Extracting Cap Kit — engineered for riders who demand precision machining, lightweight performance, and long-term durability.

CNC-machined from aerospace-grade Grade 5 Titanium (Ti-6Al-4V), this system delivers exceptional strength-to-weight efficiency at just 12.8g per set, making it a premium upgrade for both road and MTB performance builds.

Key Specifications

• Weight: ~12.8g / set
• Material:
  Grade 5 Titanium (Ti-6Al-4V)
• Thread Type:
  • Crank Cap: Left-Hand Thread (LHT)
  • Crank Bolt: Right-Hand Thread (RHT)
• Torque Specification:
  • Cap: 15Nm
  • Bolt: 40Nm
• Tool Compatibility:
  SHIMANO TL-LR15 / PARK TOOL FR-5.2 / equivalent
  (Standard Cassette Lockring Tool)

Component Specifications

Crank Bolt (BIGROCK RS)

• Weight: ~8.3g / pcs
• Tool Compatibility: 10mm Hex (Allen Key)
• Thread Direction: Right-Hand Thread (RHT)
• Recommended Torque: 40Nm

CNC-machined from Grade 5 Titanium (Ti-6Al-4V), the crank bolt delivers high tensile strength and stable torque retention, ensuring secure crank arm fixation under high-load riding conditions.

Self-Extracting Crank Cap

• Weight: ~4.5g / pcs
• Thread Direction: Left-Hand Thread (LHT)
• Recommended Torque: 15Nm
• Tool Compatibility:
  SHIMANO TL-LR15 / PARK TOOL FR-5.2 / equivalent
  (Standard Cassette Lockring Tool)

The self-extracting cap is designed for efficient crank removal while maintaining precise preload control. Its lightweight titanium construction ensures long-term corrosion resistance and consistent engagement performance.

Engineering & Manufacturing Excellence

To ensure micron-level dimensional stability under extreme thermal conditions (up to 650°C hot-forging process), each custom forging die is limited to a maximum of 300 production cycles before replacement. This controlled lifecycle guarantees consistent precision and long-term structural reliability.

All components are manufactured using military-grade CNC machining systems, ensuring tight thread engagement, stable torque performance, and vibration-resistant assembly under high-load riding conditions.

The titanium material is sourced from a certified aerospace supply chain with an average tensile strength of ≥1050 MPa, significantly exceeding conventional industrial standards (>895 MPa).

Under equivalent mechanical load, S-PARTS titanium hardware delivers steel-grade 10.9 performance characteristics, while reducing weight by approximately 50%.

Surface Finish & Color Systems

PVD Vacuum Nitriding Series

Gold / Black / Blue / Titanium

• Surface diffusion bonding
• High abrasion & corrosion resistance
• Designed for all-weather durability 

Anodized Color Series

Indigo / Candy / Green / Purple

• Multi-layer electrochemical coloring
• Deep gradient visual effect
• Built for expressive custom builds

Premium Graphic Series 

• Topographic Glacier (Ice Contour Texture)
• Great Wave Flow Finish
• Splatter Pop / Neon Splatter
• Rabbit Camo Pattern
• Snowstorm Ice Finish (not pure white color)
• Tiger / Jaguar Green-Gold

👉 Designed for riders searching:
oil slick / topographic / camo / custom titanium bike parts aesthetics

Compatibility & Usage

• Model: BIGROCK RS crank system
• Function: Self-extracting crank bolt + preload cap system
• Tool Standard: SHIMANO TL-LR15 / FR-5.2 compatible tools
  (Standard Cassette Lockring Tool)
• Recommended Torque:
  • Cap: 15Nm (Left-Hand Thread)
  • Bolt: 40Nm (Right-Hand Thread)