How long of a string should I be using on a 58 in bow?
Recurve or longbow and how old? If it's a longbow 55", older recurves(and some of the newr ones)54". Best way to tell is to measure your existing string from end of loop to end of loop off the bow.
55in
3in shorter then the bow.
There's no set rule that every bow folows. AMO specs say 3" shorter, recurve or longbow, but a lot of bows don't go by AMO specs. Many of the older recurves get a string 4" shorter, but I've seen recurve strings vary from 6" shorter (an old Herters) to 2.5" shorter; longbows from 1.5" shorter to 4" shorter.
Chad