Moveable-link suspension systems, like four-links and ladder bars, may offer the ultimate in adjustability, but there are certain drawbacks. One is expense. Another is that they are not allowed in some classes, such as NHRA Stock Eliminator. The legal CalTracs system accomplishes the goals of adjustability and adds what John Calvert refers to as "correction of the pushing point vector," but at a much lower cost. Basically, a car with a traction system that uses the "original" vector as illustrated will rise so dramatically on launch that it will unload the tires, causing wheel spin. The car then comes down, gets a good bite on the track again, rises excessively, and spins the tires again. Obviously, this is hard on elapsed times as well as parts.