The Girodisc D2-185 rear replacement braking surfaces (326 × 20 mm) allow you to replace the braking surfaces on your Subaru WRX STI’s (2018+) GIRODISC rotors while retaining the compatible rotors after inspection. These cast iron pads maintain the floating mounting’s functionality and facilitate maintenance of a braking system subjected to repeated stress. Sold in pairs, without rotors.
The cast iron track and floating assembly allow the disc to accommodate thermal expansion differences between its two parts and center itself between the brake pads. This construction also makes it easier to replace the tracks when they are worn.
New brake pads must be installed with new rotors or new rotor tracks. Their shape and compound must match the mounting configuration, the cast iron material, and the intended use; follow the specific requirements for this part number and perform the prescribed break-in procedure.
Each application is specific to its brake system, calipers, and any requirements for brake pads or spacers. Check these requirements before ordering.
Choose brake pads whose shape is compatible with the calipers, track, and/or D2-185 rotor, and whose compound is suitable for sport driving or track use. The Endless, pagid Racing, or Ferodo Racing ranges may be considered after verifying the appropriate part number.
For intensive use, we recommend compatible aviation-grade flexible hoses and high-performance brake fluid that meets the vehicle’s specifications, along with proper bleeding and fluid replacement. This recommendation complements a mounting compatible with the original hydraulic system.
When worn, replace the pads with the part number compatible with your existing rotors. Reusing a rotor for up to three pad replacements is subject to inspection of its condition, its mountings, and the mounting instructions; this number does not constitute a guaranteed service life. Use a new mounting each time you replace the pads.
What are the sizes of the D2-185 tracks for my vehicle? The part number shown measures 326 × 20 mm and mounts to the rear axle. The track height, mounting bracket, and cups must also be compatible with the mounting.
Is the product sold in pairs? Yes. It includes a left and a right component for the same axle. The brake shoes are not included.
Do I need to replace my vehicle’s brake pads?Yes. Always install new brake pads with new brake discs or new braking surfaces. Use a compound suitable for cast iron and your intended use. The metal brackets on the original brake pads and certain aftermarket pads require adjustment to clear the brake disc mounting while maintaining the parking brake. It is essential to follow the instructions and use pre-prepared pads when available.
How do I identify the left and right sides? Girodisc rotors come with a label attached to each rotor: LEFT for the left side and RIGHT for the right side, as viewed from the direction of travel. On a left-hand-drive vehicle, “LEFT” corresponds to the driver’s side and “RIGHT” to the passenger side. Follow these labels and the instructions. On models with curved internal fins, the rolling direction depends on this internal ventilation; the surface grooves alone are not sufficient to determine the side.
How do I break in this mounting on my vehicle? Follow the Girodisc procedure and the brake pad manufacturer’s instructions to build up an even transfer ply. The PDF documents below detail installation and break-in.
We have included two PDF documents below: an instruction manual for installing and breaking in the discs, and an instruction manual for installing new tracks on existing bowls. Consult the document that applies to your specific task before you begin.
