KD7721 RS-635 Rear Brake Pads - Mercedes-Benz C-Class

Barbaro Racing KD7721 RS-635 rear brake pads for Mercedes-Benz C-Class / AMG C63 and Mercedes-AMG C63 calipers. RS-635 is Barbaro's low-metallic endurance race compound (50–800°C, μ 0.40–0.52) — CEC 2025 TCS class winner. Pad shape KD7721: 146.2 × 67.6 × 17.1 mm; interchanges with FMSI D1907.

Specifications

Barbaro part number	KD7721
Compound	RS-635 — Race endurance low-metallic
Barbaro factory code (SKU)	D77212N5
Axle	Rear
Dimensions (L × H × T)	146.2 × 67.6 × 17.1 mm
Drawing note	X2 pads 146.2 x 57.9 x 17.1; X2 pads with wear-sensor tab 146.2 x 67.6 x 17.1; backing 6
Supplied as	One axle set
Also available for KD7721	KD7721 S-01 Street & Track, KD7721 CSI-01B Carbon-Ceramic

Caliper fitment

Caliper brand	Caliper	Details
Mercedes-AMG	C63 (W205) single-piston (rear)	48 mm friction face

Vehicle fitment

Make	Model	Chassis	Years	Engine / variant	Notes
Mercedes-Benz	AMG C63	W205
Mercedes-Benz	C-Class	C205, A205

Fitment is compiled from the Barbaro Racing application catalogue and Barbaro factory data, together with the vehicle listings of the interchange part numbers below. Brake packages can differ within one model — please compare your current pads with the dimensions and drawing, or send us your VIN, before ordering.

Cross-reference / interchange numbers

FMSI	D1907

Interchange numbers identify the matching pad shape. Friction material, shims and wear-sensor hardware can differ between brands.

About the RS-635 compound

RS-635 · The endurance champion

The CEC 2025 class winner. At Tianfu International Circuit, a Hongqi H6 on RS-635 ran a 200-minute stint against PAGID RST3's 120 — with less wear.

Temperature range: 50–800°C
Friction: μ 0.40–0.52 (steel disc)
Formula: Race endurance low-metallic
Discs: Steel and carbon-ceramic
CEC Championship validated — TCS class winner
200 min endurance on a single set
Ideal for: Endurance racing in heavier GTC and touring cars

RS-635 full specifications on barbaro-racing.com

About Barbaro Racing

Barbaro Racing (野蛮人) is the performance brand of the CAC Racing Division — proprietary compounds developed entirely in-house. Development begins on the dynamometer and ends on the circuit: every friction formula is bench-tested to destruction before earning the right to carry the Barbaro name. All compounds are validated against GB5763-2018 national standards; Street Series compounds are asbestos-free.