Braking Mods 3: Rotors
Brake rotors are a wear item that need to be replaced when worn to a certain level. For normal iron rotors, that’s based on thickness. For carbon rotors, it’s based on weight.
Here is the weight of a very used (and rusty) OEM 1-piece front rotor compared to a brand-new 2-piece rotor.
That's 4 lbs of weight reduction per rotor at the front. The rears see a drop as well.
The weight loss is likely a little more than what's seen in the pics above. The OEM rotors were well-worn, so they didn't weigh as much as they did when they were brand new. The 14 lbs 6 oz (6.52 kg) of weight savings seen in these pictures would probably be slightly more if we compared new-vs-new rotors (it's on my to-do list).