SKU: 16223711965

Girodisc Rear Replacement Rotor Ring Set - F8x M2, M3, M4 W/ Blue Calipers

Sale price$897.75 Regular price$997.50
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Description

Girodisc Rear Replacement Rotor Ring Set - F8x M2, M3, M4 W/ Blue CalipersGirodisc is a Braking Technology Company dedicated to developing the best quality high performance braking components and solutions. The company has been in business since 2003 and is guided under the direction of company Principal Martin Meade, who spent five years as an Engineer with Porsche Engineering Services, where he played a role in developing current Porsche technology. PRODUCT INFORMATION Need new rings for your Girodisc 2 Piece Floating

Girodisc is a Braking Technology Company dedicated to developing the best quality high performance braking components and solutions. The company has been in business since 2003 and is guided under the direction of company Principal Martin Meade, who spent five years as an Engineer with Porsche Engineering Services, where he played a role in developing current Porsche technology.

PRODUCT INFORMATION

Need new rings for your Girodisc 2-Piece Floating Rotor Set? We got them. Rings come complete with all new hardware and full instructions for re-assembly; but if you choose you can send us the hats and we will do all the re-assembly and turning of the rotors for only the cost of shipping.

This service is available for the life of your rotors. Price is for a pair of rings and 2 hardware kits. Additional hardware kits are available separately upon request.

Suitable for Girodisc Rear 2-Piece Floating Rotor Set - F8x M2, M3, M4 W/ Blue Calipers (A2-186) only.

The primary purpose of the Girodisc system is to reduce unsprung and overall vehicle weight. The secondary purpose is to increase the ventilation and cooling capacity of the brake disc while retaining it's original dimensions. This is accomplished by using two-piece disc construction. The central “hat” section of the disc is made from 6061-T6 aircraft specification aluminum.

The disc is made from cast iron, to the same specification and material as used by professional racing organizations. It is a curved vane design, developed in racing to act as a centrifugal pump to force cooling air through the disc. The rotor and hat have a floating mount system, which utilizes  high strength alloy steel drive pins, manufactured by Girodisc to our own specifications and cadmium plated for a long lasting corrosion resistance. These pins take the load from braking actions while maintaining the axial and radial float between the hat and disc. The pins are secured by grade 12 cap screws with hardened washers. In order to keep the rotors from making noise when cold, the pins are mounted with anti-noise spring clips on the rotor side which allow the rotor to grow with heat expansion but eliminate the rattle and noise associated with floating rotors. This float also allows the rotor to self center between the pads.


Important Questions Answered


What is required to install the Girodisc system?

The Girodisc system is a direct replacement for the OE disc. No modifications are necessary. The disc will bolt directly to the car and work with OE calipers and pads perfectly. Once the Girodisc system is in place, simply replace the cast iron rotor when needed. Some discs are larger in diameter and come with caliper spacers. If longer bolts are required, they are also supplied.

How does reducing weight of the braking system benefit the vehicle?

The Girodisc will generally weigh between 4 – 8 lbs less than the oe disc it will replace. This is due to the heavy cast iron hat section being replaced with lightweight, high strength aluminum. The mass of any vehicle requires energy to accelerate or decelerate. Reducing the vehicle mass improves acceleration, and requires less energy to be dissipated during deceleration. Rotating mass requires additional energy in order to increase or decrease its speed of rotation. Decreasing the mass of the disc has a great benefit due to reduction in rotational inertia. This will allow more of the braking force to be available to decelerate the vehicle, not the disc.

Additionally, the mass of the brake system is also unsprung mass. Reducing the unsprung mass has the additional benefit of improved suspension performance, resulting in enhanced ride and handling. Rotating masses require additional energy to vary the plane on which they turn. The lighter the disc, the quicker the response of the vehicle steering due to the reduction in gyroscopic effect/rotational inertia of the disc. As an example, compare the weight of the Ferrari 360 OE disc at 18.2 lbs, and the Girodisc at 14 lbs. The Girodisc is 4.2 lbs lighter per disc. Replacing all four discs will save 16.8 lbs of rotating, unsprung mass.

Why slotted discs?

The edges of the slots continuously clean and refresh the pad surface. This will allow the pads to have a maximized friction surface always available. Additionally, they prevent containments from collecting between the pad and disc interface. The disc is lightened, decreasing its rotational inertia. Slots prevent the formation of a water film on the disc in wet weather, maintaining the best brake response.

A note on drilled discs

Girodisc does not recommend drilled discsfor high performance applications. The rapid heating and cooling cycles will cause cracking on the friction surface of a drilled disc. The use of high friction or racing pads will exaggerate this condition. Most pad manufacturers specifically recommend that their race pads not be used on a drilled disc for this reason. Girodisc can drill discs for an additional fee,  if the customer is aware of the potential hazards of drilling the discs.

Note as example the cracking in this OE Ferrari 550 drilled disc after one track day. Also note this custom front disc of a Porsche 993 Turbo after hard use (see photos).


Please see photos attached


Should new discs and pads be bedded in and if so, how?

The answer is yes, for optimum performance, any time different friction materials or discs are introduced, a bedding procedure should be carried out.

Which direction should the discs rotate?

For maximum airflow and superior cooling, the Girodisc system uses curved vanes. For a curved vane internally vented disc, the geometry of the vanes dictates the direction of rotation. A curved vane disc must be installed with the vanes running back from the inside to outside diameters in the direction of rotation. Your discs will come with labels indicating their correct placement on the vehicle. Orienting the disc in this manner creates a centrifugal pump. The rotation of the disc causes air to be pumped from the center of the disc, through the vanes, and out through the outside diameter of the disc. This greatly enhances the disc’s ability to dissipate heat. Discs installed backwards have very limited cooling.

Models
  • 2 Series / F87 M2 (2016-2021) / M2 Competition
  • 2 Series / F87 M2 (2016-2021) / M2
  • 2 Series / F87 M2 (2016-2021) / M2 CS
  • 3 Series / F80 M3 (2014-2019) / M3
  • 3 Series / F80 M3 (2014-2019) / M3 Competition
  • 3 Series / F80 M3 (2014-2019) / M3 CS
  • 4 Series / F82 / F83 (2014-2019) / M4
  • 4 Series / F82 / F83 (2014-2019) / M4 Competition
  • 4 Series / F82 / F83 (2014-2019) / M4 CS
  • 4 Series / F82 / F83 (2014-2019) / M4 GTS


        Shipping Notes
        • Free Standard Shipping on $100+ Orders to the USA.
        • Except Preorder products are shipped in 48 hours.
        • Delivery to the USA:
        1. Standard Shipping : 3-10 business days
        • If time is of the essence, please consider selecting expedited delivery for faster service.
        Exchange/Return Notes
        • We offer a 30-day return/exchange service after receiving.
        • Final sale items are not eligible for returns or exchanges.
        • To process your return/exchange, please contact us at [email protected]
        • Please click here for more details>>> Return & Exchange Policy
        SKU: 16223711965

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        Jenna Smeyne
        Birmingham, US
        ★★★★★ 1
        Super wide
        Size: 13 Little Kid, Color: Taupe
        They are oddly very wide. Great for kids with wide chunky feet but for us it was not cute
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        Reviewed in the United States on May 18, 2026
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        Kindle Customer
        West Palm Beach, US
        ★★★★★ 2
        Nice but runs small
        Size: 7 Big Kid, Color: Navy
        The sandals are nice and not to hard or flimsy but they are cut very small.
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        Reviewed in the United States on April 22, 2026
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        Alexandria Knox
        Chelsea, US
        ★★★★★ 4
        Solid Kids Sandals, Overpriced Like Most Kids Shoes 🌞
        Size: 11 Little Kid, Color: Brown, Size: 11 Little Kid, Color: Brown
        My son hasn’t worn these yet since it’s December in Indiana and sandals + snow obviously don’t mix. 😂 So this review is based on first impressions rather than long term wear. That said, these seem wider than a lot of typical kids’ sandals, which I REALLY appreciate since we tend to have wider feet in our family. #hobbitfeet The quality feels pretty decent overall. They’re described as lightweight, and while they’re not insanely lightweight, they do have enough weight to feel semi-sturdy and not flimsy or cheap. I like the style and color, and I think they’ll work well for my son once warmer weather hits. My main complaint is the price. At just under $24 at the time of this review, it feels a little high for kids’ sandals and for what these are. I really feel like $20 MAX would make more sense. Kids shoes are almost always priced like adult shoes, even though they clearly use less material, and that’s hard for me to understand and wrap my mind around. Overall, these seem solid for daily wear, I just wish the price was a bit more reasonable and affordable.
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        Reviewed in the United States on December 31, 2025
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        Job
        Battle Creek, US
        ★★★★★ 5
        Great basic and timeless design
        Size: 12 Little Kid, Color: Brown
        These sandals are a great find! They’re super easy to get on and off thanks to the Velcro straps, which is a huge win for little ones learning to be more independent. The fit is adjustable and secure, so they stay in place well during all kinds of play. The cork-style footbed is comfortable and gives good support, and the overall design feels sturdy enough to handle everyday wear. They’re lightweight but still durable, and have held up really well so far. They also have a classic, versatile look that goes with just about everything, perfect for summer outfits. Overall, a reliable, comfortable sandal that’s great for active kids. Would definitely buy again!
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        Reviewed in the United States on April 24, 2026
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        Nicole
        Boise, US
        ★★★★★ 5
        Great option for boys or girls
        Size: 13 Little Kid, Color: Black, Size: 13 Little Kid, Color: Black
        This is really more of a unisex option for a sandal. I have sandals that look like this, and both of my children have worn this style. I ordered these for my daughter, with the plan to pass them down to my son if they're not too worn when she outgrows them. The style is very minimalistic, so it goes with lots of outfits. All the straps are easily adjustable, so you can get a good fit. I would say the length is true to size, but the width is maybe a bit wide. Nevertheless, the adjustable straps really help them fit well. They feel really sturdy and I appreciate that the sole has cushion to it. My daughter has worn these every day since I got them out of the closet and they're holding up well.
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        Reviewed in the United States on February 19, 2026

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