hey YD, sorry for the slow reply, I was out riding instead of talking about riding
...
There are several contributing factors to this heat reduction. One of the most common sources of heat is from the gases produced
by the bonding agents of the brake pad burning off. Under severe braking, this can actually produce a boundary layer of gas that
pushes the pad away from the rotor, which can result in excessive brake fade. Cross drilling holes in the rotor provide
an escape path for these gases (de-gassing or out-gassing are common terms), and allows the pad to stay in contact with the rotor.
Modern brake pad formulas produce much less gas than in the past, but the problem still exists. As well as de-gassing, cross-drilling
will provide better wet weather braking as water is swept through the holes.
A vented rotor can be viewed as a fan. When in motion, the vents draw air from the center of the rotor outward. The air flow, over
an increased internal surface area, very efficiently dissipates heat. Cross drilling adds to this air flow, as well as providing additional
surface cooling. It also helps the rotor cool more evenly, eliminating hot spots and greatly reducing rotor warpage. This is especially
true on heavy-duty vehicles, which, due to lower vehicle speeds, and larger tire diameters, have a much slower air flow through the
brake rotor. so there.
I could have used a few holes up on 9 today, It's still a bit damp.
oh, & no soup for you,
NEXT! :laughing