Finding longbow string length

IroquoisArcher · 05-08-2003, 07:32 PM

Hi guys. A friend is opening up an archery shop and had a longbow brought in the was bought at a yard sale. He thinks it is only a 25# as it has 25 on the handle. Overall length (measuring along the belly of the bow) is 60 5/8" . I did a search and found a post saying rule of thumb was a recurve is 4" shorter then the measured length and a longbow is 4" shorter. Does this sound right as a starting point to make it 57" ? I know things can vary. Thanks.

CT Bowhunter · 05-08-2003, 07:47 PM

Hopefully LBR will be along soon and help. Depends on the design. My 62" Lil Magnum longbow uses a 60" string, and my 64" Crusader longbow uses a 61" string.

Dick4bows · 05-09-2003, 05:58 AM

Ahhh.... the advantages of the flemish string! Dick

Broker · 05-09-2003, 07:44 AM

I know many will disagree, but the AMO standards are for the string length to be 3" less than the AMO bow length for both recurve & longbow. The standards are very clear, there is no room for interpertation. That said, many like a higher brace height, and use a shorter string than they should. (By the way I have a copy of the AMO spec sheets pertaining to string length.)

Darrel

Floxter · 05-09-2003, 02:07 PM

Broker is correct that the AMO standard for non-compound bows is 3" shorter than the measured bow length. However, I' ve got one longbow that takes a string 2" shorter and a recurve that takes a string 4.5" shorter. So it' s really a question of trial and error.

LBR · 05-09-2003, 03:36 PM

Yep--what Floxter said. AMO standard just don' t work with every bow--I' ve made strings for longbows that were 2" shorter than the AMO bow length and I used to own an old Herter' s recurve that stated right on the bow that it got a string 6" shorter than the AMO bow length. It will vary with the bow design and shooter' s preferance. The easiest way to find out, or at least get close, it to make a " string" from some nylon twine (the type used for trotlines works fine). Shorten or lengthen until you get the brace height you desire, then measure it--then you will know what length string to get.

Chad

IroquoisArcher · 05-11-2003, 11:20 AM

Thanks guys. Again this is a bow the guy picked up for $5.00. I can see some fractures (at least it looks more then just the grain to me) in the handle so he will be told it is probrably better off as a wall piece.
But while on this subject (and again I know it will vary), what is the " average" brace height you usually run into for a 61" ish bow?

Robert Williams · 05-13-2003, 11:24 AM

AMO standards are similar to spine charts in that they' re a good starting point and rule of thumb but that' s about it.

There are so many variables that it' s impossible to make a " standard" unless all the bows are of the same design geometry and length. 66 inch recurve bows typically will have a brace height of 8.25 to 8.75 inches for best performance. 68 inch recurves 8.75 to 9.25 and 70 inch 9.25 to 9.75.

Additionally, since AMO is measured along the limb and not from end to end, the curve of the bow will affect the " length" . This isn' t such a problematic deviation with longbows because they' re more or less straight. As a rule of thumb, the longer the recurve, the more it will lean toward 4 inches. The shorter, the more it will lean toward 3. Longbows are typically close to 3 inches.

Now if we' re talking B-50.... allow about an inch and a half for stretch on a 60" bow if you' re building the string yourself. And for those who don' t know how to stretch their own B50 strings, just string the bow and put it on your lap belly up (string toward you - handle on your lap). Then press down very firmly on both limbs. The limbs will act as levers on fulcrum (the riser) and provide you the mechanical advantage necessary to stretch that string properly. You can shoot 200 arrows out of a bow and still not take all the stretch out of a B-50 string, but once you do take it out, it becomes very stable. " shooting out the stretch" just doesn' t work.