Why ductile iron rotors

Brake rotors are most commonly offered in solid and ventilated designs. In many modern vehicles the front rotors are ventilated and the rears are solid, however, there are also many vehicles that offer ventilated rotors front and rear.

Ventilated discs have a space between the brake surfaces that allow for airflow to pass through the rotor for cooling purposes.

A better option is the curved vane, which acts much like a fan blade, swirling the air and forcing it outward from the hub center by taking advantage of the spinning motion of the rotor during driving. DBA rotors employ specifically designed pillars with a layout and post shape that works much like the curved vane when it comes to heat extraction, but offers even less obstruction to the airflow which reduces turbulence and increases the flow of hot air as it exits the rotor. While slotted rotors may look cool, the real advantage of slotted rotors is an increase in braking power, in many cases up to percent.

Often slotted rotors have a higher resistance to brake judder, an increased cooling affect and a higher operating friction level. Sounds great right? Unfortunately, all this magic comes with a price. Hope this sheds some light. More Info Traditional materials and manufacturing methods have kept the door open to problems associated with thermal stress fracturing or simply put, cracking. This phenomenon is primarily focused on the use of gray irons and particularly individual mold casting.

That process creates difficult to control porosity problems during the casting procedure. Porosity weakens the structure and reliability suffers. Then using a computer controlled continuous cast process to produce high quality heat treated iron ingots giant bars, often referred to as billet.

These are then cut into plates with highly specialized saws and CNC machined. The rotors are double disk ground to a tight tolerance and finish to insure flatness and parallelism. This material and method eliminates porosity, creates a homogenous and consistent grain matrix structure that is both very stable and very strong. See Tech Talk: Ductile vs. Over the years, cast iron has proven itself to be an excellent rotor material providing superior "feel" and producing a higher coefficient of friction at the friction couple.

If you're looking for genuinely improved performance in terms of both braking power and modulation, then this is for you. If rain and or high humidity is the rule and rust potential a concern, you may wish to consider the alternative in our new AXIS range which is now offered in premium series Stainless Steel as well. Generally speaking, most organic semi-metallic brake pads are good for use on iron rotors.

Iron: Grey Vs. This style of rotor does not have a venting area in the middle of the rotor. So far I have come up with the grey cast iron having about twice the thermal conductivity of the ductile iron.

Most OEM motorcycle brake rotors being made out of stainless steel, the thermal conductivity is very low comparitavely, I believe the ductile iron's thermal conductivity to be suffient in preventing localized hot spots while in use. Is this acurate?

Also, the grey cast iron has about half the tensile strength of ductile iron. Would the ductile iron's extra strength help prevent cracks from forming or warping from repeated heat cycling even more than the lower grey iron?

Or does this just help if there is some bending put into the rotor? Also, how is the coefficient of friction affected? Manufactured in our Billet Iron and the Cobra stainless. Manufactured at our standard spec of 5mm for use with the OE Brembo 4-pad caliper, positions this new offering in our Performance Upgrade Series. The new design provides a significantly higher overall level of capability compared to the standard issue OE system.

However, this is not a race-spec floater. For additional information, please use our contact form , and we will get back to you ASAP! There does indeed exist a universal prohibition against the use of sintered metal pads on generic cast iron rotors, we have the same warning. But this caveat is more specifically targeted to old-school gray cast iron and particularly of the individual molding, gravity feed casting type. That combination was and is inherently problematic with a propensity towards suffering from thermal stress induced fracturing.

Not good. Firstly, it is CNC machined from American made high grade nodular ductile iron, not gray iron.