Hi guys.... I tried searching and looked in the FSM but came up empty... Got a quick question..

What's the thickness of the stock brake rotors, new? I know the minimum allowable thickness is 22mm front / 16mm rear (per the FSM)... But I want to try to figure my wear in terms of percentage...

Thanks!
-Dmitri

edit

Thanks to RX8Maine, here are the full specs for brake rotor thickness:

Front: 24mm new, 22mm minimum (need to be replaced)
Rear: 18mm new, 16mm minimum (a new set measured at 18.1mm)

 

If your saying the stock thickness is 22mm then just take your 8 to a brake shope. Have them measure your rotors. That right there will tell you how thin they are from when you first got them. IF you have owned the car from the start based on your driving and / or if you just got new rotors.

 

Gesundheit!

I do not know the original size. I went out to Sears and bought a micrometer so I know the current size (incidentally, my front right is way out of spec for thickness variation... but I'm not concerned about that for now).

22mm is the point at which the FSM tells you to change them. Mine are at 22.8. I wanted to figure out what the original thickness was, so I could say either "oh, they're still at 20%" or "crap, they're at 3%" or something...

Anyone?

 

i would also like to know!

 

Going to a meet tonight... Hopefully someone will have a car new enough to give me a good idea...

 

Bump! The meet fell through (ended up at the wrong place)... Does anyone know???

 

They are listed as 24mm stock, per specifications, but I have never actually taken a micrometer to a new one.

Mine are at 23.2mm after 17,000 miles and 3 track days (approx 4 hours track duty total) on OEM pads.

I would love to know the original thickness of the rear rotors. I haven't found it anywhere.

 

Cool, thanks for the info! That would mean my fronts are at approx 40% (59k miles, 13 of those mine, no track days that I know of)... The rears I am less concerned about but if someone could dig up the numbers that would be great!

 

Rear brake Pad

min pad thickness 2.0 mm or .079 inches


Rear disc

min disc plate thickness 16mm or .063

Run out limit is the same for both front and rear. Set at .05 mm or .002 "

 

Razz1: Thanks, but I can get that from the FSM I am trying to figure out the original size when new...

 

As it turns out, I have a new rear rotor on order. I'll measure it when it arrives.

 

^May I ask why?

 

The old one didn't like meeting the backing plate of the inner pad.

Mazda never thought to put wear indicators on the rear, so I used up a rear pad at the track and was probably dragging the backing plate for at least part of my last session, and on the drive home.

 

New rear rotor is rated 18mm in thickness and measured to 18.1mm on the micrometer.

 

Sweet! Thanks all... Will update the first post