shmucklebuckle

So, over in the OT Forum, a technical discussion came up (really!) about warped rotors. Apparently rotors never or very very very seldomly actually warp (in the sense that they themselves develope some sort of wave or dish to them, usually quantified by thickness variation or runout). Streckfu's 951 (Daniel) posted this interesting and seemingly accurate article on brake wear:

http://www.stoptech.com/tech_info/wp...rakedisk.shtml


I was kind of floored to hear "No, there's no such thing as warped rotors," but, damn, the article sure makes sense. Are there any personal experiences out there by those of you who work in service or are knowledgable enthusiasts that would either agree or disagree with the theory? I think I'm going to move the the "agree with the article camp," just want to hear what everyone else thinks about it!

L8 APEKS

Well, I am too tired to read...but my Volvo steering wheel shakes like a puppy passing a pine cone under moderate braking. This would seem to be caused by the rotors becoming deformed in some way. If turning a rotor (making the surface flat again) solves the problem, and we generally accept "warp" as the term used to decribe deformed rotors - then I would say warping DOES exist, and any debate may possibly be a case of semantics.

Then again, I didn't read the article. I will tomorrow.

shmucklebuckle

Semantics, nice! The rotors accumulate uneven pad material, which makes them "warped" in a sense; the only stipulation being that the rotor itself is still the same dimensions/shape.

michaelathome

I am guesing that if you were to heat up a block/disk of metal or brake disk and apply 450lbs of pressure it will bend.

I know that the denser the material is the less it is subject to movement. As an example a platinum ring, the ones you wear on your hand, rarely loose mass, it is only moved to another location. Steel is a much more maliable material subject to more natural oxidizing etc.

I guess if you had platinum rotors and adequate pressure you could stop a car doing 80mph w/out losing material but warping the disk. With the right amoung of pressure you should be able to move it/the material back to where it came from and un-warp the disk.

Michael

streckfu's

Read the link as it explains very well what occurs.

bader$

I know that when you check them you check for both runout and thickness variation. The Thickness variation is from uneven wear, usually from improper mounting (uneven torque of the wheels). However lateral runout I am told is from excessive heat which I would think is warpage. With that said most rotors I resurface are from thicknes variation not lateral runout problems.

streckfu's

So if I take a brick and dry some mud on it, is the brick 'thicker'? No. It just has dry mud on it.

The rotor is not 'deforemed' nor warped. It has pad material stuck on it. Turning the rotor cleans that crap off it.

Fishey

Its false...

Rotors warp like potato chips if conditions are right, I have pictures that show it.. I just can't find the file right now..

BeerBurner

I've had to return brand-new rotors because they were warped. Seriously, I laid them on a flat surface and they weren't flush. Granted, this was due to a manufacturing defect, bad storage or something else along those lines and not the result of heat since they were bad before they even got on the car.

Does that count?

BB.

streckfu's

They do qualify with this:

joseph mitro

i'll go with the pad deposits camp.

Matt H

Bader is spot on.
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Yabo

damn volvos.. mine does the same...

toddbailey

I have a dial indicator to prove how wrong this claim is. But I don't need to use it, I can feel it when I stop or slow down.

streckfu's

Can you be sure you're not measuring uneven wear instead of heat induced warpage?