And I have noted the "pretty basic stuff." As the pad contact area thins, the cross sectional area of the conductive heat transfer to the rest of the rotor is constricted at the edge of the wear zone. This is the point where there is that roughly 20 reduction. But the VAST majority of the heat dissipation is radiation and convection off the heated surface of the rotor. The "heat sink" effect of a thicker rotor is very small compared to the overall heat transfer to the environment. The rotor is not serving as a heat capacitor to any significant extent. Q = U*A*Delta T for convective heat transfer. Radiative heat transfer is controlled by the Stephan-Boltzman equation and is proportional to the difference between the 4th power of the surface and the ambient temperatures.