Spiral Balance length

Question

Old balance is half rod and half heavy spring. Top half is rod and bottom is spring. Total length is 24 1/2" to blue bushing. I replaced it with a 24" solid rod, but it is not long enough. With window in the closed position, I have 1 1/4" gap at bottom of window. Do I need a 25" rod or 26"?

Paul · Accepted Answer

Series 900-25 blue tip spirals measure 25 3/4" long. The 26" balances measure 26 3/4".