At What Thickness Do Rotors Need To Be Replaced?

At What Thickness Do Rotors Need To Be Replaced? At what thickness do rotors need to be replaced? However, manufacturers provide minimum thicknesses for their rotors. Shimano recommends that its rotors, which start out 1.8mm thick, should be replaced when the braking surface has been reduced to 1.5mm. This information is given on the rotor;