GiroDisc A2-149 Slotted 2-Piece Rear Rotors for 2010-2023 Audi RS5 / RS4-RS5 B9

Vehicle Fitment

• Audi RS5 (B8: 2010-2016) - rear axle
• Audi RS5 (B9: 2017-2023) - rear axle
• Audi RS4 / RS5 (B9 platform, 2017-2023) with OEM rear calipers - rear axle

Features

• 2-piece floating rotor design - cast-iron rotor ring + 6061-T6 aluminum hat to reduce unsprung & rotating mass
• Slotted & vented disc surface - improves pad bite, evacuates gases/debris, and enhances fade resistance under heavy use
• Curved-vane internal ventilation - draws cooling air through rotor to improve thermal management during repeated braking
• Floating-mount hardware: cadmium-plated alloy-steel drive pins + Belleville washers and spring-clip retainers - allows thermal expansion while preventing rotor rattle
• Direct bolt-on replacement - works with OEM rear hubs and calipers, no modification required
• Reusable-hat design - when rotor rings wear out you can replace only the rings, re-using aluminum hats to reduce long-term maintenance cost
• Reduced unsprung and rotating mass compared to stock, improving suspension response, braking modulation, and rear-end stability under braking
• Manufactured in USA from GiroDisc proprietary cast-iron rings and domestically sourced aluminum hats

Specifications

• Part Number: A2-149
• Type: 2-Piece Floating Rear Brake Rotors (slotted & vented)
• Material: Cast-iron ring + 6061-T6 aluminum hat (anodized)
• Rotor Style: Slotted + vented, curved-vane internal ventilation
• Mounting System: Floating mount - steel drive pins + Belleville washers + spring clips/fasteners
• Sold As: Pair (rear left + right rotors) including floating-mount hardware

Included Components

• 2x Rear brake rotors (left & right), 2-piece floating, slotted & vented
• Floating-mount hardware: drive pins, Belleville washers, spring-clip retainers / cap screws

Product Description

GiroDisc A2-149 is a premium rear rotor upgrade engineered for performance-oriented Audi RS5 (B8 and B9), and compatible RS4/RS5 B9 cars - offering a direct bolt-on replacement for stock rear rotors. By replacing the factory one-piece rotors with a lightweight, floating 2-piece design, A2-149 reduces unsprung and rotating mass - resulting in improved suspension response, more stable braking, and better rear-end control under hard braking or spirited driving. The slotted and vented disc surface, combined with curved-vane ventilation, enhances heat dissipation and pad-gas/debris purge - reducing brake fade and delivering more consistent braking performance under repeated use.

The floating-mount hardware permits thermal expansion and self-centering while preventing common issues like rotor rattle or vibration on cold start. Because the rotor hats are reusable, maintenance becomes more cost-effective over time: worn rings can be replaced individually without discarding the entire rotor assembly. For owners of RS5 or compatible RS4/RS5 B9 platforms seeking a durable, high-performance rear braking solution without altering calipers or brake bias - A2-149 offers an excellent balance of performance, durability, and practicality.