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  • Tuning a recurve bow

    From the many queries I get on tuning a recurve bow:
    (Covered in more detail in "Mastering Bow Tuning", as is tuning a compound bow).
    Assumptions:
    - The bow's physical length is about correct for your draw length.
    - Adjustable limb alignment.
    - Adjustable draw weight.
    - Arrows of a size that will work.
    - The arrows are about level with the back of the riser when at full draw.
    - You have a sight and a clicker.
    - You have a good bowhand position and are not twisting the riser.

    If your arrows are the correct size, the following process is easy, fast, accurate and repeatable.

    Steps:
    - Select the correct string length. This should ensure that the correct amount of string is sitting around the recurve on each limb. It is best to use the manufacturer's recommended brace height.
    - Set the tiller. Make the top tiller about 1/8" greater than the bottom tiller.
    - Align the limbs. You need to end up with the string running centrally down the limbs and the riser, and for the riser not to be twisted off to one side.
    - Set the pressure button so that there is zero movement (I put a match in it). Then adjust the centreshot so that the arrow is sitting exactly on centre.
    - Shoot some fletched and some unfletched arrows at about 15-20M. Adjust the nocking point so that the fletched and unfletched arrows hit at the same height.
    - Adjust the bow's draw weight so that the fletched and unfletched arrows hit the same place horizontally. Note that if the arrows are not the correct size, this step will not be possible, and there will be little you can do to fix it (sell the arrows and buy new ones - with a recurve bow you really do need to get the exact correct size, one size wrong will not tune correctly even with much frustrating tinkering). If the bow draw weight will not go high enough you can try a lighter string. If the bow draw weight will not go low enough you can try a heavier string.
    - Still with the solid pressure button, adjust your sight so that you are grouping around the centre of the target.
    - Now, do not change the sight setting. Take the match out of the pressure button and adjust the spring tension to "something nice".
    - Now that you have some give in the spring, you will need to push the arrow out a little from true centreshot, so adjust the pressure button position.
    - Shoot some arrows and see where the centre of the group is. If the arrows are to the left then move the pressure button to the right, and vice versa.
    - Shoot some fletched arrows at a longer distance and check that they seem to be flying well.
    - Powder test to ensure that the rear of the arrow is not striking the rest or pressure button.
    - It should now be working pretty well.

    Note that we are not fiddling with the spring tension to try to get the fletched and unfletched arrows to group together. It does not work like that. The key adjustment is changing the bow's draw weight.

    Note that we tune a barebow recurve in essentially an identical manner (using a sight and a clicker).

    Note that we tune a compound bow shot with fingers in an identical manner.
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  • #2
    I tuned up Jessica Walters bow using Jim's method over xmas and she stepped out with it fresh and shot a 324 at 50m on a small face.
    I have tuned a number of recurves using this method and the traditional hit-miss method and Jim's is faster and alway produces great arrow flight and good groups.
    Urban Archery
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    Before enlightenment: Chop wood, carry water
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    • #3
      The US coach Dick Tone (of Cavalier) has used and publicized this method for more than 30 years. With all due respect to Jim, I don't think it's exactly news.

      (It seems a lot of people have published this in various places without giving any credit to Dick.)

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      • #4
        gt,
        Yes, agreed, same as used by Dick Tone (and important to note his contribution, as you say).
        (I also used it back in the early 1970's, having thought back then about the physics of what happens to the arrow).
        Scout strings and stabilisers
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        • #5
          I can certainly vouch for this method. It gets the bow matched properly to the arrows, and builds in a good deal of ìforgivenessî. You can probably get exactly the same result with the method in the Easton tuning guide, provided that the arrows are pretty much correct for the bow, but I quite like the stiff plunger element of the method given above.

          People have some funny ideas about the stiff plunger element, though. Itís clear to me that the stiff plunger removes any masking effects of the pressure button so arrow spine becomes critical, which means that you need to find the draw weight where the arrows spine best. The result is that the tuned pressure button compensates for inconsistencies in the loose rather than masking any mismatch between arrows and bow.

          Yet some very intelligent and knowledgeable people seem to think the stiff plunger element has something to do with centre shot. Odd.
          Gimme back my bullets

          Club: Phoenix Bowmen, Halifax, UK

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          • #6
            Originally posted by James Park
            - Shoot some arrows and see where the centre of the group is. If the arrows are to the left then move the pressure button to the right, and vice versa.
            Just to clarify Jim: are you saying to adjust the centreshot (ie move the static resting position of the button) or adjust the spring tension (ie the "dynamic centreshot")? The quote above suggests the former, but I suspect you meant the latter....
            I have no problem with alcohol-free days; I have them all the time. It is the evenings I have trouble with.

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            • #7
              Sandy, I meant the former, that is: adjust the position of the pressure button.
              You could also adjust the spring tension, but I think adjusting the position is easier and faster. It also avoids problems of sometimes having archers end up with very weak spring tensions and the button bottoming out.
              Scout strings and stabilisers
              Accurate Sights
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              • #8
                Originally posted by James Park
                Sandy, I meant the former, that is: adjust the position of the pressure button.
                You could also adjust the spring tension, but I think adjusting the position is easier and faster. It also avoids problems of sometimes having archers end up with very weak spring tensions and the button bottoming out.
                So if you then powder tested and found contact, would you suggest changing the spring tension and then readjusting the centreshot to bring the group back to the gold?
                I have no problem with alcohol-free days; I have them all the time. It is the evenings I have trouble with.

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                • #9
                  Sandy,
                  Yes.
                  Assuming you have an arrow that is appropriately matched to the bow, contact is most likely to be around the arrow's rear node (about 150mm from the nock, or thereabouts). The rear node does pass very close to the rest and button, and contact there is the most difficult one to deal with.
                  If it is contact with the fletches and everything else seems ok, I would try rotating the nock a little.
                  Scout strings and stabilisers
                  Accurate Sights
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                  • #10
                    Thanks that info is great but how do you select a string?

                    I have a question some say for a 68in bow that you should have it 6in shorter that the bow others 3in. Could some one help me to confirm the theory so I can order a new string.

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                    • #11
                      Originally posted by redline350
                      I have a question some say for a 68in bow that you should have it 6in shorter that the bow others 3in. Could some one help me to confirm the theory so I can order a new string.
                      No one can give you a definite answer unless you supply your limbs and riser combination and their lengths at least. Basic rule of thumb from some sources say 2 1/2 to 3 1/2 inches shorter than the bow height / length. However, that also depends on the type of string material you're going to order. If say, you're going to order something that will creep and creep and creep and also has some stretch in the bargain, like Angel ASB Dyneema, then you would only go for perhaps 2 to 3 inches maximum. The guy who makes my strings from this material makes my strings at 64 1/2 inches.

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                      • #12
                        As I remember it, a 68" bow is defined as a bow requiring a 65" string.
                        Scout strings and stabilisers
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                        • #13
                          Thank you for the information about the string!

                          Hi Guys,

                          Thanks for that information, at times you ask archery shops you can get more confused and then end up with the wriong thing. I thought I would do some research and try for myself, so I have paid for will try this saturday.
                          redline350

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                          • #14
                            Originally posted by redline350
                            Hi Guys,

                            Thanks for that information, at times you ask archery shops you can get more confused and then end up with the wriong thing. I thought I would do some research and try for myself, so I have paid for will try this saturday.
                            redline350
                            You should talk to Apexrob (Mr Bling Strings) His strings are spot on!
                            If you're not confused you don't know what's going on

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                            • #15
                              Redline

                              Have you considered making your own strings??
                              Regards, Grahame.

                              Shoot a Selfbow, embrace Wood Arrows, discover Vintage, be a Trendsetter.

                              Kathy Kirby

                              Imagineering is Creative.

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