GiroDisc 370mm Rear Rotor Replacement Rings for BMW G8X M2/M3/M4
This is a pair of replacement rotor rings for the GiroDisc 370mm two-piece rear rotor assembly on the BMW G8X platform, letting you renew the braking surface without replacing the reusable aluminum hats.
What It Fits
BMW M2 (G87, 2023-present), M3 (G80, 2020-present), and M4 (G82/G83, 2020-present) equipped with the GiroDisc 370mm rear rotor assembly (A2-282), on cars without carbon ceramic brakes.
What It Does
Replaces worn rotor rings on the existing GiroDisc two-piece rear rotor assembly. The rings are machined from a high-carbon iron casting to GiroDisc’s specification, with 48 curved vanes that pull air through the hub for cooling under hard use.
Construction
High-carbon iron rotor rings paired with your existing 6061-T6 aluminum hats (black anodized). Reassembly uses spring clips and Belleville washers for race-ready float without hardware noise on the street.
What’s Included
- 2 replacement rotor rings (1 pair, rear)
- Replacement mounting hardware (spring clips, Belleville washers, drive pin hardware)
Compatibility Limits
These rings fit GiroDisc hats only and are not designed for use with other brands’ two-piece hats, including factory two-piece rotor hats. You must already own the complete GiroDisc 370mm rear rotor assembly (A2-282) before these rings can be installed. These are the 370mm rings for the standard A2-282 rotor, not the 380mm rings (D2-322) used with the carbon ceramic iron conversion rotor (A2-322); confirm which rotor is installed before ordering. GiroDisc recommends replacement at a minimum ring thickness of 22mm, or sooner if a crack reaches the edge of the ring.
Installation
- Remove the wheel and the existing GiroDisc rear rotor assembly from the vehicle per the applicable factory service procedure.
- Separate the aluminum hat from the worn rotor ring by removing the spring clips, Belleville washers, and drive pin hardware.
- Clean the hat and inspect it for wear or damage before reuse.
- Install the new ring onto the hat using the included replacement hardware, following GiroDisc’s assembly sequence.
- Reinstall the completed rotor assembly and torque the wheel and caliper hardware to factory specification.
FAQ
Do I need the complete rotor first to use these rings?
Yes. These are replacement rings only and fit GiroDisc hats exclusively, so you must already own the complete GiroDisc rear rotor assembly (A2-282) before fitting them.
What is the difference between the 370mm and 380mm GiroDisc rings for the G8X?
The 370mm rings (D2-282) are for the standard A2-282 rear rotor. The 380mm rings (D2-322) are for the carbon ceramic iron conversion rotor (A2-322). Confirm which rotor you have before ordering.
Are these rings sold individually or in pairs?
Sold and priced per pair, which is one complete set of rear rings.
Is hardware included?
Yes, replacement hardware is included with the rings.
Can I use these rings with a different brand’s two-piece hat?
No. Unless specifically noted, GiroDisc replacement rings are designed to work with GiroDisc hats only.
When should I replace these rings?
GiroDisc recommends replacement at a minimum thickness of 22mm, or sooner if a crack extends to the edge of the ring.
Do these fit cars with carbon ceramic brakes?
No, this rear rotor assembly is for G8X cars without carbon ceramic brakes.
What models does this fit?
BMW M2 (G87), M3 (G80), and M4 (G82/G83) from the G8X generation.
