R1 Concepts 623-54139L RNC Series Cross-Drilled Brake Rotor - Left

The R1 Concepts 623-54139L RNC Series Cross-Drilled Brake Rotor is a direct-fit, single left-side replacement rotor engineered to deliver enhanced stopping performance over a standard OEM disc. Built to OEM specifications for a no-modification installation, this rotor is ideal for drivers seeking a meaningful performance upgrade for daily driving, light towing, or street performance use.

Key Features:

• Cross-Drilled Design: Precision-drilled holes are chamfered and countersunk to reduce heat buildup, dissipate gases, and minimize the risk of cracking during normal use
• G3000 Grade Cast Iron Construction: Provides excellent thermal stability, consistent braking performance, and long-term durability
• Zinc Plated Finish: Protective zinc coating guards the hub, hat, and vane structure against corrosion, extending rotor life and maintaining a clean appearance between pad replacements
• OEM Direct Fit: Designed to match original equipment specifications — no modifications, adapters, or special hardware required
• Left Side (Single Rotor): Part number 623-54139L is the driver's side rotor; sold individually
• Double Disc Ground Braking Surface: Promotes faster, more even brake pad bed-in and contributes to quieter, smoother stopping from the first use

Upon initial installation, the zinc coating on the braking surface will wear away naturally during the bed-in process, leaving the protective coating intact on the hub and internal vane structure. A proper brake bed-in procedure is recommended to maximize rotor and pad performance and longevity.