Eliminating warped rotors forever!
May 7, 2006
The Bottom Line Go with high quality ceramic pads, save money by going with OEM quality throw-away rotors, and eliminate a lot of disc brake woes.
It seems to be the bane of many a car owner: You made a panic stop; now every time you press the brake pedal, it vibrates as your car shudders and shakes to a stop. Your rotors are warped. Again. Wouldn't it be nice if you could just get rotors that would never warp? Well, you can...and the secret isn't in the rotors, but rather in the pads.
How disc brakes work
First, we need to identify the cause of the problem, and the root of the problem lies in how disc brakes work. Remember the 10 speed bicycle you rode as a kid? You'd squeeze the brake lever on the handlebars, and two rubber pads would close in on the wheel rim, bringing your bike to a stop. Disc brakes in a car work in much the same manner; except instead of rubber pads closing in on the rim, you have brake pads closing in on a rotor, which you can think of as a smaller wheel within your bigger wheel. Whether or not you have ABS, all disc brakes work in this manner. The rotor is made out of iron, while the pads can be made from various different materials. When the pads close in on the rotor, friction is created. It's this friction that slows the car down. A by-product of that friction is heat. A great deal of heat is generated in even the softest, slowest of stops. In a panic stop or in hard braking, it may be possible for the rotors to get red hot. Sometimes, it can get so hot that the brake fluid can start to boil!
Heat - the enemy
It's this intense heat that causes rotors to warp. With conventional and even metallic brake pads, the brake pads and rotor rub against each other; the pads make the rotor hotter, while the rotor makes the pads hotter. This keeps going back and forth between the pads and the rotors until they get intensely hot. Then, when the wheel finally stops turning, you have a piping hot pad sitting in one place of the rotor. What happens then is the rest of the rotor cools off a lot quicker than the spot where the hot pads are sitting. This is where the warpage comes from. Another danger is brake fade; the pads and rotor can get so intensely hot in hard braking, their ability to generate friction is greatly reduced.
The solution - ceramics
Ceramics have amazing properties when it comes to heat. They can withstand extremely high temperatures without distorting; more importantly, ceramic is very good at not transferring heat. Ceramic tiles are used on the bottom of the space shuttle to protect it from burning up on re-entry. Now, you can get brake pads that use ceramic material.
Ceramic brake pads aren't made entirely of ceramics; they're a blend of materials, including ceramic. They also usually contain copper fibers; those of you who cook understand that copper is very good at transmitting heat. What this gives you is: a) A pad that does not get very hot at all, and b) A pad that can wick heat away from the rotors by way of those copper fibers. By eliminating heat, you eliminate the problem of brake fade. You also eliminate the problem of warped rotors.
What about the rotors?
Many people have tried various types of rotors; some are drilled, some are slotted. Some people buy "Premium" rotors. The problem is, they're all still made out of iron. Drilling and slotting only reduces the amount of surface area, which can hurt braking performance unless you go with bigger rotors and pads. It still doesn't change the properties of the iron, and can lead to other problems such as premature cracking. Consider too that the original purpose for drilling holes in brake rotors was to permit the brake pads to outgas as they heated up. This was a problem with organic brake pads manufactured circa 1960 on performance cars driven at high altitudes. Today's modern brake pads do not outgas.
By using ceramic pads, you won't even need to use the "Premium" rotors. The purpose of premium rotors is that they can be "Turned" (have the surface shaved off of them) when they become pitted and/or warped. Since modern ceramic pads are so good at keeping rotor temperatures down, there is no reason to use anything better than the OEM quality throw-away low-cost rotors!
Added benefit: Longer life, cleaner rims, no more noise!
Heat is what kills conventional brake pads and rotors. By staying cooler, ceramic pads used with ordinary throw-away rotors will last quite a bit longer. The dust produced is less, and is a lot lighter in colour, which means your front rims aren't going to look dirty with all that nasty brake dust. Finally, the materials used in ceramic pads is such that the squeal generated is at a frequency too high for humans to hear. Quiet brakes, cleaner rims (or hubcaps), longer life...and no more warped rotors. With the added safety of eliminating the dreaded brake fade.
If you just scrolled on down to the bottom to get the bottom line, here it is: Next time you need to service your disc brakes, go ahead with conventional OEM quality throw-away rotors, and use high quality ceramic pads. You'll be saving money, and possibly your life, in the long run.