Quote:
Originally Posted by rh71
Front rotor minimum spec is 28.4MM when replacing pads but 26.0MM when not replacing pads. Rear rotor minimum spec is 18.4MM.
My measurements after 4 years: front 28.2MM and rear 19.1MM.
My first question is why would rear minimum specs be different from fronts? I know they definitely seem to wear faster (as do the rear pads). My SA also said that I shouldn't worry about the rotors unless I start feeling they're warped (brake vibration, etc.). Hard to believe - what exactly should I be looking out for, because I won't be doing pads for another 3-4 years at this rate (25k miles in 4 years)? Surprising too, with my 80% local driving. What are the measurements of brand new rotors anyway?
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Front brakes do 70% of the stopping, so they are built heavier to start. More mass means that they can take more hard stops before getting too hot. In general, front brakes will wear faster from stopping. Brakes are also used for traction control, so faster wear on the rears can be related to the traction control intervening more often (given the rear wheel bias of power delivery).
As rotors get thinner, they will fade faster. You may not ever notice it, if you don't get them hot enough to fade.
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