Most spring driven American antique clocks are overpowered (they have springs that are stronger than necessary). Even at age 100 years (give or take) the mainsprings are almost always strong enough to operate the clock reliably, assuming that the clock has been repaired properly, including POLISHING THE PIVOTS and installing bushings.
A spring should be replaced only if it is damaged (cracked or rusty). Some of the very old American springs (for instance from the 1850’s – 1860’s) are quite rough, yet they have operated the clock for all these years, and there is no reason to doubt that they will continue to operate the clock well. Yes, an old spring could break at any time, BUT SO COULD A NEW SPRING! I leave the original spring in the clock unless it is damaged. I install a weaker spring if the existing one is too strong.
French clocks are delicate, yet very efficient in operation, and I have not often experienced mainsprings that are too weak. The usual problem with French clock mainsprings is a torn hole in the outer end. A new hole should be made in the end, unless the spring is too short from having this operation done too many times.
Share this post: