Buildings from 1990 in this part of the valley were built to a code that assumed less thermal cycling than what an Arizona commercial door actually sees over 30-plus summers. Severe heat here doesn't just wear the spring metal - it dries out the nylon idler bearings and cooks the lubricant out of the rollers faster than the same hardware would fail in a milder climate. On a commercial door that opens and closes dozens of times a day, that shows up as a hard stop partway through the cycle, or a track that binds right when the sun hits the wall it's mounted on. Because the housing stock and the commercial stock nearby both cluster around that same 1990-2002 window, the failure pattern repeats: original torsion springs, original bearing plates, original openers, all aging out around the same year. We're not guessing when we quote a spring-and-bearing job together instead of just the spring - it's usually both, because they were installed together and they've taken the same 33 summers.