Originally Posted by
Lazyass
You're wrong. When you bed-in properly, the surface of the rotors gets covered in an invisible thin film from the brake pads, which is more "grabby" than bare metal when the pads contact it. It also helps cut down the squealing issue.
But wouldn't there already be an invisible thin film on the rotor that had been laid down previously from the pads that I am replacing? Hmmm. It seems that Part Tool thinks something else is involved:
"New disc pads may require a “burn in” period. Solvents from manufacturing are burned off from the heat of braking. Braking performance will improve after the burn in period."
https://www.parktool.com/blog/repair...and-adjustment