Bow Tuning – Basic Setup

IMG_7304For a beginner, if you purchased your bow from an archery shop, hopefully they worked with you to “basically” setup and tune it for you. If you are in the unfortunate situation were you do not have a pro shop near by and/or purchased your bow online you will need to perform the basic setup yourself. This may be a difficult task if it is your first bow and you are a green horn to archery. Shooting form has the most impact on your performance and you need to be relatively consistent to see any major impact from bow tuning.

That said in the first couple of blogs, I will give a basic overview of how to setup your bow so you can begin shooting with it. Later in the series we will discuss the intricacies of tuning each area of the bow.

For any bow setup you should have a couple of basic bow tuning tools

IMG_7604Bow Square: T-shaped tool for measuring brace height, tiller and nock position.

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IMG_7606Nock Pliers:  Specially designed pliers for installing nock points.

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IMG_7608Bow Stringer: Provides a safe and convenient way to string recurve or long bows.

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You may also need an Allen Wrench Set (Hex Keys), Pliers, adjustable wrench, scissors and/or various screwdrivers depending on the composition of your equipment. Reference the manufacturer’s manuals for necessary tools. There are a ton of additional bow tuning tools such as a pressure button measuring tool, bow scale, electronic chronograph, bow press and leveling tools. These are optional and will not be used for the basic tuning.

Completely assemble your bow, for a quick and simple step-by-step guide check out my earlier post about Putting an Olympic Bow Together.

Make sure you gather all the pieces that you are going to use including the riser, limbs, stabilizer system, string, nock, arrow rest, sight, clicker and plunger. It is important to start with everything when tuning, since even one change can have you starting all over again.  Start by making sure that all the pieces fit together, and are correctly assembled so you have a tight fit.

In the first blog we will make sure your limb alignment is correct, the string and brace height are within specifications, and the tiller is properly set so the limbs are correctly set. Olympic bows are typically take-down bows with risers that have International Limb Fittings (ILF) so you can easily replace them. It is very important that limbs are aligned straight and that both limbs are aligned with the center of the grip. Some risers ILF slots can be adjusted side-to-side and you may need to make some adjustments to align the limbs.

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For good limb alignments the things to check are…

  • The limbs are correctly installed and the top limbs in the in top slot, and bottom in the bottom. (this may sound obvious but it would not be the first time someone got their limbs mixed up)
  • The string is lined up with the center of each limb and the center of the grip.
  • The limbs are not twisted – check out my earlier blog about Twisted Limbs.

brace-heightNext we need to make sure you are using the correct string for the bow. This is measured using the brace height or the distance between the center of the string and the grip when the bow is strung using a bow square. Each bow manufacturer provides the specific tolerances for the brace height however the following chart is a pretty good guide.

62” Bow            7 3/4″ – 8 1/4″              197 – 210 mm
64” Bow            8” – 8 1/2”                    203 – 216 mm
66” Bow            8 1/4” – 8 3/4”              210 – 223 mm
68” Bow            8 1/2” – 9”                    216 – 229 mm
70” Bow            8 3/4” – 9 1/2”              223 – 242 mm

If your brace height is just slightly out of range you can try to add a couple of string twists to adjust within the specific tolerance however never put more that 20 twists in a string.

tiller-measureNext we need to make sure the correct amount of draw weight is shared between the limbs. The difference between the top tiller and the bottom tiller will effect the bow reaction on release and your ability to hold steady at full draw and aim. Your hand on the grip is centered in the bow however your arrow is actually above center, the bottom limbs needs to be slightly heavier to compensate. This is accomplished on an Olympic bow using the adjustable tiller. Most risers are shipped with the tillers adjusted to the correct depth. Adjusting the tiller is an extremely advanced bow tuning technique, and should ONLY be adjusted by a someone with experience. The thing for you to check is to make sure that top tiller is about 1/8” to 1/4″ (3-8 mm) greater than the bottom tiller, if not take your bow to a professional pro-shop or coach to help you adjust it.

In the next post, we will cover installing the arrow rest, nocking point and setting up your center shot.

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Bow Tuning – A Simplified Series for Beginners

IMG_7304Your bow is  very personal to you and should be tuned specifically to you and your shooting style. Since there are tons of in-depth, technical articles about bow tuning produced by many organizations and manufacturers, my goal is to simplify the concepts for beginner archers. Although, my primarily focus will be an Olympic recurve bow, some or most, if not all, the principals can be applied to other disciplines.

In this series we will discuss, but not limit to, nocking points, bowstring fit, centering, clearance, brace height, sight alignment, tiller, clicker, plunger adjustment and discuss various tuning methods. Remember that basic step-up and tuning can be done quickly to get you started however advanced tuning is a time consuming task through trial and error.  Proper shooting technique is the first thing every archer should focus on. If you are still struggling with the basics then get your bow basically setup and work on consistency. From there, a well tuned bow can help compensate for personal idiosyncrasies and help you achieve the maximum performance.

So, in preparation for this series, review and ensure you have the correct equipment for you. You need to have equipment you can use. If the bow is too small or light, or alternatively too heavy, in-depth tuning is not going to provide many advantages. Alternatively, if your equipment is just above or below were you need to be; advanced tuning can help rein a bow in. Also, make sure you have selected the correct arrows for your setup. Review my Arrow Series about arrow selection to make sure you have selected arrows that are best for you.

StudyingAlways remember that there are several steps to properly tune your bow for maximum performance. You should record every adjustment so you are able to retrace your steps should an adjustment provide negative results. Remember to adjust only one thing at a time and then test. Remember that even one piece of new equipment will require bow tuning and the amount will depend on the importance of that piece. For example, a new plunger a little bit of tuning and new limbs with higher poundage means you may be starting from square one.

Bow tuning is an advanced technique and should be only attempted by archers with at least a good understanding the bow mechanics. I recommend you employ the knowledge and experience of a trained coach. I still work with my coach to tune any new bow that I receive, since a second or third pair of eyes can really help make the difference between a good tuning and perfection.

Arrows Series – Part 7: Center Shot and Archer’s Paradox

Now that you have determined the arrows you should use you need to fine-tune your bow to maximize your arrows consistency. Most people think that once you set up a plunger and a nocking point it is all good to go, however that is not the case. The center shot of your arrow is one of the most over looked things when setting up a bow.

The center shot is where the arrow rests on the bow when looking behind it.  When setting up your center shot the arrow needs to be completely behind the string. Most traditional bows do not have a cut-away in the riser and the arrow has to deflect around the handle with something called archer’s paradox.

Archer’s Paradox: The term was coined by Robert P. Elmer in the 1930s. The paradox refers to the phenomenon that in order to strike the center of the target, the arrow must be pointed slightly to the side of the target. Modern use of the term has caused the interpretation of it to be corrupted and the bending of the arrow is often considered incorrectly to be archer’s paradox.

In order to be accurate, an arrow must have the correct stiffness, or “spine”, to flex out of the way of the bow and return back to the correct path as it leaves the bow. Incorrect spine results in unpredictable contact between the arrow and the bow, therefore unpredictable forces on the arrow as it leaves the bow, and therefore reduced accuracy.[1] Additionally, if an archer shoots several arrows with different spine, even if they clear the bow they will be deflected on launch by different amounts and so will strike in different places. Competition archers therefore strive not only for arrows that have a spine within a suitable range for their bow, but also for highly consistent spine within sets of arrows. (Wikipedia)

For an Olympic archer, ideally your set up should be 100% behind the string. Some people actually require the arrow lean a little to the opposite side of your riser so that the arrow can get past the bow without hitting it. You can reduce the effects of “Archers Paradox” by adding spin to the arrow by fletching your vanes or feathers with an offset or helical. It is critical that the arrow must have the correct spine so it can bend around the bow, so the fletchings do not touch anything for consistent arrow flight.

Therefore, once again I stress, for proper safety and best performance, arrows need to match your entire bow setup.