GiroDisc 2-Piece Slotted Front Rotors 2015-2021 BMW M3, M4, M2

GiroDisc slotted 2-piece front rotors for the 2015-2021 BMW M3, M4, M2. Each rotor pairs a slotted iron ring with a lightweight aluminum hat, so it runs cooler and weighs less than a one-piece disc. GiroDisc builds its rotors for drivers who take their cars to the track, and they stay quiet and smooth enough for daily use.

Floating 2-piece design

GiroDisc builds its 2-piece rotors around a slotted iron ring and a separate aluminum center hat. The ring is GiroDisc's own cast iron with curved internal vanes that pump cooling air through the disc, which keeps temperatures in check through long track sessions. High-strength drive pins join ring and hat and let the ring float, so it can grow with heat and center itself between the pads without warping the hat. The aluminum hat also cuts rotating and unsprung weight compared with a one-piece iron disc, which helps acceleration, turn-in and suspension response.

Quiet on the street

Anti-noise spring hardware keeps the floating ring from the cold rattle that older floating designs are known for, so the rotors work as well on a weekend drive as they do on track.

Reusable hats

Because the hat is a separate part, you only replace the iron when it wears out. New GiroDisc rings (D1-194) bolt onto the hats you already have, which costs much less over time than buying complete rotors. Replace the rings when they reach minimum thickness, or sooner if a crack reaches the outer edge.

What's Included

Two assembled front rotors, one for each side, with each iron ring already mounted to its aluminum hat. Brake pads are not included.

Specifications

Fitment notes

Compatible with both 9660 and 9668 caliper variants. The product photo is GiroDisc's representative image of its 2-piece rotors.

Fitment