Since there seems to be a wide range of understanding of the terms discussed here, to make sure everyone is on same page, roll center is the geometric location on a chassis determined by the suspension linkages as they move thru their respective arcs, and the height of that derived roll center in regards to the measured height of the COG, determines how long the theoretical vertical lever arm is between those two points. That distance is important, as it determines how much the chassis "rolls" when cornering, longer=more. The front and rear usually have different values, intentionally. How did I do?