A door built around 1980 has had roughly four decades of cycles on its original spring, assuming nobody's replaced it. Springs are rated by cycle count, not by calendar years, but age still shows: paint flaking off the coils, a spring that looks stretched compared to its neighbor, a door that's gotten noticeably heavier to lift by hand. The mild temperate climate here doesn't add the freeze-thaw stress you'd see somewhere with real winters, so most of what we find is straightforward mechanical fatigue and old lubrication that's gone gummy, not rust-through or ice-cracked panels. On the older end of Fallbrook's housing stock we also see more single-torsion-spring setups on double doors, a configuration that's harder on the one spring you've got and fails without much warning.