Even Raybestos's premium PG Plus rotors come pre-warped right out of the box.

Andrew Paule <lsboogy@qwest.net> wrote in message news:<opNZa.4$kU4.23875@news.uswest.net>...
> If your rotors "warp" when hot, but are true when cold, you have a big
> problem with the metal structure of your rotors. This is the old
> bimetal spring (like in a thermostat) - means you are running lower
> quality rotors like MasterBlasters experience. Get some good rotors on
> the car, and this won't happen anymore.
>
> Andrew
>
> MasterBlaster wrote:
>
> >"alan" wrote
> >
> >
> >
> >>So I've heard of this problem with Hondas where the rotors can sometimes
> >>"warp" when hot. I think I have this same problem too. When the rotors
> >>are cold, I don't feel any shimmy in the steering wheel, but when I heat
> >>them up I can feel it pretty bad. According to an article on stoptech,
> >>most rotors don't actually bend, but just develop "sticky" spots. So my
> >>guess is that my rotors aren't actually bent, but somehow the sticky
> >>spots get stickier when the rotors get warm. Does that sound
> >>reasonable? Are OEM brake pads abrasive enough (when cold) to scrub
> >>away this sticky spot?
> >>
> >>
> >
> >Not "sticky"... more like "softer" or "harder" spots where the metal's grain structure
> >is different. After all, most of the cheap rotors are made in the back of a shack in some
> >third-world country where they melt down old cars, tin cans, broken AK-47s, or whatever
> >they can find. I very much doubt the metal is "pure" anything all the way through, or that
> >they properly cool them after casting to minimize distortion.
> >
> >A few months back, I ordered some rotors. Right out of the box, I found 5 or 6 ventilation
> >holes right next to each other were still 1/3 full of casting flash that I couldn't chip out, the
> >internal fins were mismatched, like they didn't get the casting molds lined up properly, and
> >the vent slots wobbled, though the friction surface was straight (the only machined area).
> >
> >The second set were the same, except that on both of these rotors, one surface was
> >already covered with rust.
> >
> >We changed brands.... clean, dead-straight, fully-machined, perfectly matched cores.
> >
> >The first set of pads was crap too. One pad had friction material that was twice as thick on
> >the inside edge as the outer, and not *quite* as flat as I'd like... it looked like a wedge-shaped
> >potato chip had been stuck to the backing plate with too much glue, which had squished out
> >around the sides. Real quality stuff.
> >
> >
> >