The thickness of new rotors (Brembo)
 

A while back I checked the thickness of my REAR rotors. They were at 9 mm and a bit rusty, so I decided to order brand new Brembo blanks, since I was doing a complete pad change and flush, among other things.

When I received the new rotors, I decided to check the thickness for the hell of it, and found them to be at 9 mm (both rotors). Stamped around the circumference of the rotor it states as 8 mm as being the mininum thickness.

If it starts out at 9mm to begin with (brand new), then do I only have 1 mm before its time to throw them out again?

Is this fact true? Maybe I should continue using my old rotors? The old rotors have been on the car since I bought in Oct. 2000. Please advise.

As you can see, the rear brakes don't have much meat on them to begin with. when you take 1mm off of it, you cut off about 12% of the rotors material.

would you want to keep driving your car if you'd cut 12% of the mass of your front rotors off?


Thing is, the rear brakes are small because they don't get used much. You don't need a lot of material back there to begin with. If/when you turn them (every 60k or so is usually about normal) then you don't take much off. If you do, then replace them- as you did.

Let's put it this way: at 65kkms my rear rotors were still Okay, but at 85kkms I had to replace them.