Determine Coil Weight for Coil Balance

Thanks for posting. Is this the only coil spring that was attached to the shoe? If so, see the S170-407 7 pound spring. The closest match we have to the shoe is the 15-192. 

However, note that our replacements were intended for Certainteed windows. We've found the 15-192 shoe has difficulty fitting a Simonton window. You may be able to get it to work by rubbing down the alignment nubs on the shoe's surface, but even then I can't promise it will work. 

Because of these difficulties, we've devised an alternative solution: our 15-259 shoe should fit your window. The catch is you'll have to replace the coil balances entirely with the Series 159. The video below shows how to do this.