String length

[Billyjack]

I am restringing a BP H90 thats 58" what should the string length be?

[LittleBen]

easiest way is measure the old string.

If the bow is marked 58" AMO then the string length should be 55" when stretched with a 100lb weight(3" shorter than the bow length).

If you're using a dacron string, the string will be 54" before stretching. If you're using a FF string it will be 55" without stretching b/c FF is extremely low creep/stretch compared to dacron and will be still be nearly 55" when stretched.

Since I assume it is an older bow and you're replacing a dacron (b-50) string, I'd replace it with another b-50 string. It will be a 58" AMO string, or will be marked 55" or 54" string depending on if the measurement is made before or after stretching. I've had good luck with FF on some older bows, but I also had to redo the tip overlays with phenolic to prevent damage. B-50 is the simple easy safe choice.