What is the alternative to an extension spring?

The main alternative to extension springs is a torsion spring system. Torsion springs sit horizontally on a steel shaft above the door and use winding bars to load tension, which they release gradually as the door opens. Torsion systems last roughly twice as long as extension springs, around 15,000 to 20,000 cycles versus 7,000 to 10,000, balance the door more smoothly, and are far safer when they break because the spring stays contained on the shaft rather than flying through the garage. Wayne Dalton's TorqueMaster system is a third option, with the spring sealed inside an enclosed tube. Converting from extension to torsion typically costs 300 to 600 dollars but eliminates the safety cable through-spring requirement and adds years of life.