The build: calipers, rotors, pads, wheels
| Item | Front axle | Rear axle |
|---|---|---|
| Caliper | AP Racing AP7410, 10-piston forged | AP9582 four-piston forged, plus separate electronic parking brake caliper |
| Rotor size | 420 mm | 410 mm |
| Rotor | STOPFLEX long-fiber carbon ceramic | STOPFLEX long-fiber carbon ceramic |
| Pads | STOPFLEX high-performance ceramic | STOPFLEX high-performance ceramic |
| Minimum wheel | 21-inch | 21-inch |
| Scope | Full front and rear carbon ceramic conversion | Full front and rear carbon ceramic conversion |
Check this first: The 420mm front and 410mm rear rotors with the AP7410 10-piston calipers need a minimum 21-inch wheel. Confirm your wheel diameter, spoke profile, and inner barrel clearance before you order.
What the upgrade actually does for the 9X
| STOPFLEX feature | Why it matters on the 9X | What you notice |
|---|---|---|
| 10-piston front caliper, 420mm rotor | The 9X is a heavy, high-torque SUV. More piston area and a bigger disc give the front axle more clamping authority where most of the braking load lands. | Firmer, more linear pedal under hard freeway braking with a full cabin. |
| Long-fiber carbon ceramic rotors | Steel rotors lose friction stability as they heat up. Carbon ceramic holds a tested surface friction near 0.3μ even at 900°C. | Pedal stays consistent on long mountain descents and repeat high-speed stops instead of going long. |
| Roughly half the rotor weight | Carbon ceramic discs weigh about half what same-size iron discs do, so you pull mass off all four corners. | Steering feels a touch sharper and the ride settles quicker over rough pavement. |
| STOPFLEX ceramic pads | The pad compound is matched to the carbon ceramic surface, so it runs clean and bites from cold. | Very little brake dust on the gold wheels, and normal bite even around -20°C on the first stop. |
| Corrosion-proof rotor face | Cast iron rusts fast on a vehicle that sits or sees winter roads. | Discs don't rust after rain or storage, so the hardware stays clean behind open-spoke wheels. |
What gets better
- Firmer, more predictable pedal when the SUV is loaded and moving fast
- Heat-stable braking on long grades and repeat hard stops
- Less unsprung weight at every corner, helping steering and ride
- Very low brake dust with the matched STOPFLEX ceramic pads
- Rotors that don't rust and last far longer than iron under street use
What to confirm first
- Wheel diameter is at least 21 inches
- Spoke profile and inner barrel clear the 10-piston caliper
- You want the full front and rear conversion, not one axle
- Rear keeps a separate EPB caliper, so factory parking brake stays intact
- Pads and rotors stay matched as a STOPFLEX set
If you're not sure your car matches the spec shown here, send us your details and we'll confirm Zeekr 9X fitment before you order through our Zeekr CCB collection.
Build Gallery
FAQ
Does the rear big brake kit keep the Zeekr 9X electronic parking brake working?
Yes. The rear runs a dual-caliper setup: an AP9582 four-piston braking caliper plus a separate electronic parking brake caliper, so factory EPB, hill-hold, and Auto-Hold all keep working after the upgrade.
What size wheels do I need to clear the 420mm STOPFLEX rotors?
You need at least a 21-inch wheel. The 420mm front rotors and 10-piston AP7410 calipers are physically large, and 21 inches is the minimum diameter that clears the hardware.
Do carbon ceramic brakes work in cold weather, or do they need heat first?
Paired with STOPFLEX high-performance ceramic street pads, cold bite stays normal. Even around -20°C on the very first stop, the brakes deliver consistent, quiet stopping power for daily driving.
How much unsprung weight does the STOPFLEX carbon ceramic upgrade save?
STOPFLEX carbon ceramic rotors weigh roughly half as much as same-size cast iron discs. On a heavy flagship SUV like the Zeekr 9X, dropping that weight at all four corners sharpens steering response and helps ride compliance.
Will the STOPFLEX carbon ceramic rotors rust after rain or winter driving?
No. Unlike cast iron rotors, STOPFLEX carbon ceramic discs do not rust after rain or long storage, so the hardware stays clean behind the Zeekr 9X open-spoke wheels.
