How to tell if you have 'REAL' Brembo rotor blanks or their lesser knock-offs.
Let me first start by saying that the company that I have been working with has done a great job on customer service. I have paid for one set of rotors, and they have sent 2 additional front sets based on my word alone that the rotors were warped.
This is meant as a guide to help people who are looking for aftermarket brakes to get what they are paying for rather than blindly trusting brake company X that they are getting 'Brembo' blanks.
To be very clear, when I called and specifically asked what kind of blanks they use, they said over the phone in an e-mail that they ONLY use Brembo blanks. What I got the first two times was anything BUT Brembo. Both rotors pictured below came from the SAME Company, and from the same shipping location. But what you will see is that there is a BIG DIFFERENCE.
Indicator #1 - Logo
The Brembo rotors have a Brembo Logo and stamp on the brake lip. Duh, you would think that would be a no brainer but I blindly trusted the supplier. Well REAL Brembo brakes have this stamp. They also have either a part number or serial number stamped on the edge. Mine had the numbers 09793110. The stampings on the Brembo blanks are also MUCH cleaner and more easily distinguishable from the knock offs. The Brembo's came in a thick brown cardboard box. The knockoffs came in a thin white cardboard box.
Indicator #2 - Rotor Hat Front
Brembo - has 5 lug holes, and 2 screw holes (to brake the rotor from the hub after it eventually rusts on).
Knockoff - has 5 lug holes plus 10 more 'extra' holes which are good for, who knows what?
Indicator #3 - Rotor Hat Rear
Brembo - Nicely machined inside hat. Notice also how much farther their vanes of the rotor extend in vs. the other.
Knockoff - Roughly cast hat, with a wide gap between the rotor vanes and the braking surface. Not machined at all.
Indicator #4 - Weight*
Brembo - 19lbs, 9.4 oz
Knockoff - 17lbs, 12.8oz
What's worse you ask? The knockoff is NOT drilled and is lighter, by almost 2 POUNDS! Shouldn't all those holes in the Brembo rotor make them LIGHTER?
* The two white things are business cards that kept the rotor from rolling off the scale. They did not add a significant amount of weight.
Indicator #6 - Surface Thickness and Vane Coverage ***MOST IMPORTANT***
Brembo - has two equal and identical braking surfaces. Each side is EXACTLY 10mm thick.
Knockoff - has one side that is 9mm thick and the other is 8mm thick! Roughly 15% less braking surface material! ( I measured the other 3 front rotors they sent and they were all different: 8mm/9.5mm, 9mm/9mm (not too bad), 9mm/8mm. No two rotors were the same.)
Brembo - Vanes extend out to the very outer edge of the braking surface (both inside and outside)
Knockoff - Vanes are sunken into the rotor surface by 6mm (on the inside and outside), meaning there is less material connecting the two rotor surfaces.
Why is indicator #6 the most important?
When you brake the rotor absorbs heat. If one side of the rotor is thicker than the other, the thinner side gets hotter FASTER than the other. The side that gets hotter expands faster and more acutely. This induces brake shudder/vibration/shake/whatever you want to call it. This is compounded by the fact that the vanes that keep the rotor intact are SHORTER on the knockoff than on the Brembo. Compound this by the fact that the braking surface is thinner, thereby reducing the amount of heat the brake as a whole can absorb. Combine all three of these things and you have an inferior rotor.
Why does it only vibrate at higher speeds and it feels smooth at lower/surface street speeds?
At surface street speeds you don't build up enough heat to create a large enough heat differential between the two sides of the rotor. But at highway speeds, this process is accomplished pretty easily.
Do I have to buy Brembo/Bradi?
I would, and I would guess that most others would agree with me. In my opinion, there is not a chance in hell that these two brakes came from the same factory or even the same wholesale distributor. The CSR told me that the initial 2 sets of rotors I received were Brembo rotors. I call BS. The Brembo rotor is clearly of superior build, and quality.
How can you protect yourself when buying?
1. Specify that your rotors be the Brembo brand, with the stamp that proves it.
2. Inspect the rotors before you install them, as it seems that most places will not accept used equipment.
3. Compare the rotors you purchased to the pictures I have listed here. If they look like the knockoff, strongly consider asking the company for a replacement set.
In the end the company made things right, and sent me Free of Charge 3 sets of front rotors. The last of which were genuine Brembo, and the ones that finally did not vibrate. They were patient, and I am sure would like to keep their good name. This post is NOT intended to bash the company, but rather educate the consumer.
Why don't I talk about the rears?
Since the fronts provide 75-80% of the braking power, the rear brake's job is much easier. As a result, it is very unlikely that the rear brakes will cause much of an issue. Also, since I ended up getting genuine Brembo brakes for the rear in the first place, they were not defective.
Best of luck.