[Euro Ford Fan]

P-51,Nov 15 2005, 12: Wrote:Simon, ever use a cheese grater?

That's why/how they wear pads faster.  Same with slotting.

Cross drilling is 1950's technology, and has not place on anything using modern pad materials.  Modern pads, whether street or race just do not off-gas the way old pads did.  There is no gas that needs to escape. 

So, there is no real benefit to cross drilling.  Yet it costs more money and wears your pads faster.  They also critically reduce the structural integrity of the rotor.  They crack, and will eventually break apart.

Slotting does have some use, but not because of off-gassing.  It's primary benefit is to "clean" the pads, particularly in rally.  If mud or water gets on the rotor, the slots help clear it.  It doesn't help braking otherwise.

Both of them can actually hinder dry braking performance, because they remove surface area and mass from the rotor.

There is a movement to BAN drilled rotors from racetracks, because of their inherent risk of structural failure.
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Rob structural failure I would agree with yes, I've had a rotor fail when I first took my XR to the Glen back in 1999. I never ran a cross drilled rotor again after that.

I'm still not all that convinced that they wear out that much sooner. In a street application how much would you consider a good pad life to be? I change rotors and pads when I change from my summer to winter tires? 2 full seasons like tires maybe 20,000 KM is plenty of life.

Steve: I'll agree with that.