for a longbow that is 63 inches from tip to tip you would need a string that is 60 inches rite or would you measure from the string grooves

Measure from groove to groove along the back of the bow following the lines of the bow,use a seamstress tape(cloth tape). Mostly for longbows it is 3" less than amo length. If you have an old string, measur it.

Danny

To get the AMO bow length, measure from the "top" of one string groove, following the contour of the limbs, through the center of the riser, to the "top" of the other string groove.  If the bow was built to AMO specs, it will get a string 3" shorter than that measurement--but a lot of bows aren't built to AMO specs.

Chad

Measurements will get you in the ballpark +- 1". You can have 3 different bows that measure exactly 64" and they'll need 3 different string lengths. That's why AMO isn't based on physical bow length...O.L.

Quote..That's why AMO isn't based on physical bow length...O.L. [/QB]

What is it based on, O.L.?

Tom, String length. "String length for proper brace plus 3"=AMO bow length. 61" string = 64" AMO. If it wasn't this way you could have 4 different bows of the same "length" but use 2 or 3 different string lengths for proper brace. Some say it's confusing, the only thing that causes confusion is others NOT following AMO standards. Best bet if unsure would be to measure an existing string stretched on 1/4" dowels....O.L.

O.L., that makes perfect sense.
Another question, though: Let's say a bowyer builds a new bow...not copying anyone else's recipe or layout - how does he know what the proper brace height is?  Experimenting with feel and sound, performance, etc.?

ttt

O.L. is correct--the actual AMO bow measurement is based on the length of the string, but it's all just "ballpark" measurements since two identical bows may need a slightly different string length for optimal tuning.

If you have no string to start with, measuring the bow (as stated above) will get you close, but as O.L. said it's also a ballpark measurement.

Chad