A 2-piece rotor construction not only allows the rotor to be significantly lighter, but is also allows us to make it a fully floating piece. A 1-piece rotor and even 2-piece bolted together rotor are fixed to each other with no allowable movement. As the rotor heats up the iron will expand. The friction ring will actually grow slightly larger in diameter. The hat will also grow as the rotor heats up. In time this leads to weakening the rotor and ultimately leading to cracking and warping. By using a special drive pin assembly with an elongated hole in the friction ring, we can allow the hat to “float” from the rotor, therefor making the hat and the rotor to expand and contract freely and un-opposed to one another. This allows you to run the rotor through countless heat cycles without having to worry about warping or cracking.