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
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>>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?
>>
>>
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>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.
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