Pinched from Bikerader, where it had been pinched from somewhere else. Magura start thicker but all others are much of a muchness. Using thicker rotors is likely to give you pad rub.
Sram rotors seem expensive – their flat plate are as much as floating from other manufacturers but one Roter is pretty much like any other in use except for Shimano XT have an ally core with a steel wear layer (or those fancy vented hopes)
Magura’s minimum recommended rotor thickness is 1.7mm. At that thickness, Magura recommends replacing them for several reasons, one being reduced heat stability. Stefan Pahl, Magura’s product manager for its bicycle division says, “In the past we had the rotor thickness limit at 1.7mm. With the Storm and Storm SL rotors we even have increased that limit to 1.8mm (which is also laser printed on the rotor, on one of its spokes).” So you can wear the rotors down by 0.2mm down from 2.0mm. The reason for the high recommended thickness is not only heat stability, but also structural stability and reduced squealing.
For Hope’s 140mm diameter and 160mm diameter floating discs, the minimum recommended rotor thickness is 1.4mm (they are 1.60mm +0.05mm when new). For all the rest of Hope’s discs, floating or plain, minimum thickness is 1.5mm (they are 1.80mm +0.05mm when new).
Hayes rotors start out life at 1.75mm to 1.78mm thick, depending on rotor diameter. Hayes’s minimum thickness call out is 1.52mm and is marked on all Hayes rotors.
Shimano rotors are made 1.8mm thick and should be replaced when the thickness has been reduced to 1.5mm. Since 2010, the 1.5mm minimum recommended rotor thickness has been printed on Shimano rotors.
[..] , SRAM/Avid rotors seem to begin life at 1.85mm thickness, tech advice to replace at 1.5