GiroDisc Rear Replacement Rings 2021-2027 BMW M3, M4, M2

GiroDisc slotted replacement rear rings for the 2021-2027 BMW M3, M4, M2. When the iron on your 2-piece rotors wears out, these rings bolt back onto your existing GiroDisc hats, so you replace only the part that wears. It is the most cost-effective way to keep a track car stopping well over many seasons.

How the rings work

A 2-piece rotor splits into an iron ring that wears and an aluminum hat that does not. These rings are GiroDisc's own cast iron with curved internal vanes that pump cooling air through the disc, and a slotted face that keeps the pad surface fresh. They mount to your existing GiroDisc hats (A2-322) with floating drive pins, so the ring can grow with heat and center itself between the pads.

Unless GiroDisc notes otherwise, its replacement rings are designed to work only with GiroDisc hats. They are not made for other brands, or for the hats on cars that came with 2-piece rotors from the factory.

When to replace them

Swap the rings when they reach 26 mm thickness, or sooner if a crack reaches the outer edge of the ring. Bed in new pads with the new rings for the best pedal feel. Reusing the hats saves weight and money every time the iron is due.

What's Included

Two slotted iron rings. New drive pin hardware is also supplied. Hats are not included: you reuse your existing GiroDisc hats.

Specifications

Fitment notes

The product photo is GiroDisc's representative image of its replacement rings.

Fitment