rear brake rotor thickness?

erkishhorde · August 05, 2009, 08:52:13 AM

My rear rotor specs don't seem to be matching my Haynes manual so I'm curious what you guys are running. I have what I believe is a stock rotor and, as far as I know, it's the original with just under 57k miles on it. Haynes manual says standard rotor thickness is 3.9-4.1mm and min. thickness should be 3.6mm.

What I've got is a rotor that is about 4.32mm at it's thickest point (the unworn section) and min thickness is 3.89mm. It's got a noticeable change in thickness to it if you're running your finger over it but it's not a sharp change like a groove. Should I replace this rotor?

Thinking about it a bit, it seems that the Haynes is telling you to replace the rotor when it's seen about 10% wear and that's about what I've got. But going straight by the numbers, I've got a rotor that was originally thicker than what they say it should be, but it's also still thicker than the min. thickness.

edit: Just took my pads off. Haha, I TOTALLY neglected my rear pads and wore through the material on one side and put some small grooves on my rotor. I think I'm going to replace it anyway.

edit again: Just got a reply from Jeff at BrakeTech. The rotors were originally 4.5mm thick and min. thickness is 4.2mm. But, unfortunately they're not in stock right now but he says they hope to have them again around the end of the year.

Speeddog · August 05, 2009, 11:41:26 AM

Don't you have a full-floating BrakeTech rotor on the rear?

erkishhorde · August 05, 2009, 01:52:39 PM

Oh, that's not stock?

It rattles.

Then what should I be using as my replacement specs?

Speeddog · August 05, 2009, 01:57:27 PM

Dunno what the spec is, but Jeff at BrakeTech would know 951 471-3476

erkishhorde · August 06, 2009, 11:06:19 AM

Just got a reply from Jeff at BrakeTech. The rotors were originally 4.5mm thick and min. thickness is 4.2mm. But, unfortunately they're not in stock right now but he says they hope to have them again around the end of the year. He also sent me a picture of the Brake Tech floating rear rotor so that I can confirm that it is a Brake Tech rotor. It is.

Speeddog · August 06, 2009, 10:05:03 PM

Well, it's not the greatest outcome, but now you know the score. $:-\$

erkishhorde · August 06, 2009, 10:52:47 PM

Yeah, I don't really want to spend the money on a new rotor right now either so it kinda works out. I should be able to get by with just new pads for a while. Thanks for pointing me to Jeff.

Langanobob · August 07, 2009, 05:32:23 AM

Quote from: erkishhorde on August 06, 2009, 10:52:47 PM
Yeah, I don't really want to spend the money on a new rotor right now either so it kinda works out. I should be able to get by with just new pads for a while. Thanks for pointing me to Jeff.

Yeah, that's what I'd do. Done it numerous times on cars although never on a bike. The new pads will seat to your grooved rotor surface so when you eventually do get the new rotor you'll also have to get new pads again. Or, sand the pads flat but hardly seems worth it.

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rear brake rotor thickness?