San Marino is a small town - 3,807 households, tucked about 3 miles from Pasadena. That size matters more than people think. It means we're not running a dozen spring jobs a week here like we might in a bigger suburb; it means the calls we do get tend to be on doors that have sat quiet a long time, on original hardware nobody's touched since the house was built.
That's the real reason we tell San Marino owners not to DIY a spring swap. A torsion spring holds enough stored energy to break a wrist or worse, and on a house built in 1943 the drum, cable, and bearing plate are often original or close to it - not a straightforward match to what you'll find at a hardware store. Guessing at wire gauge on old hardware is how a spring gets replaced twice.
We're honest about the limit here too: if the whole assembly - track, drum, bearing plates - is original 1940s stock, sometimes a spring swap alone doesn't fix the real problem, which is worn mounting hardware underneath it. We'll tell you when that's the case instead of selling you a spring and leaving the rest to fail next year.