Torsion Powered Vehicle

[Concillian]

Agreed. Considering fatigue, springs are virtually guaranteed to fail in the lifetime of the car. Fatigue is a decrease in the yield strength of a material under a load over a given period of time. As the springs are held in torsion or twisted the metal will just keep getting weaker until the thing will eventually explode into twisted shrapnel.

Springs are generally made of materials that have a high fatigue limit and their operating window is generally chosen so that they are within their fatigue limit. What this means is that under normal operating conditions, a spring will not continually weaken until it fails... unless there was a poor materials selection process.

it's part of why you don't see aluminum springs. Most aluminum alloys have a fatigue limit that is essentially zero, so they degrade with time. Steel and nickel alloys that springs are usually made from have relatively high fatigue limits.