Bow Tuning – Advanced Tuning

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So far in this series, we started by discussing the basic Olympic recurve bow setup. We covered what tools you require for bow tuning and to basically setup your bow. This included limb alignment, how to measure, installing the arrow rest, nocking point and setting up your basic center shot.

Now that your bow is basically setup, you have been practicing with it and have a fairly consistent arrow group it is time to do some advanced tuning of your bow. 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 always 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.  To avoid massive amounts of frustration, it is very important to focus on changing and tuning one thing at a time. Read my earlier blog about Consistency and Change.

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Next we will focus on individual areas for you to tune such as nocking points, bowstring fit, centering, clearance, brace height, sight alignment, tiller, clicker and plunger adjustment. Since I already created several blogs about tuning specific components your bow, you should start by reviewing the following…

Sight : Following the arrow and adjusting your sights

Clicker : Adjusting and shooting with a Clicker.

Arrows and various tuning methods : Arrow Series – Part 8 – Fine Tuning and Numbering

Remember, bow tuning is an advanced technique and if you can I recommend you employ the knowledge and experience of a trained coach, since another pair of eyes can really help make the difference between a good tuning and perfection. In the next part of the series we will continue and take a deeper dive into the remaining areas of your bow that can be tuned. 

Bow Tuning – Basic Setup continued

IMG_7304Now that your bow is together we need to make sure the arrow rest is installed correctly, install a nocking point and adjust the center-shot. It is my recommendation to always install the arrow rest before installing your nocking point. So, let’s start with the arrow rest.

Installing the Arrow Rest

There are a lot of types or arrows rests available on the market. Check out my earlier blog about the various types of arrow rests. For this blog, I will be focusing on the most commonly used one for Olympics style bows, the pressure/plunger rest.

The main purpose of the arrow rest is to hold the arrow in place until the arrow is shot. A  plunger style arrow rest is designed with a support arm just long enough to hold the arrow, with a slight inward angle to the bow, and it moves out of the way with the shot.  They should also be adjusted so that the support arm does not protrude beyond the outside of the arrow. This is to minimize contact with the arrow and minimize impact on the arrow flight. Lastly the arrow rest must be positioned so the plunger/pressure button is square to the center of the arrow.

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Olympic recurve bows come with a threaded hole for the plunger/pressure button and the arrow rest typically is installed and centered over the hole as the arrow rest and plunger work in conjunction with each other. Note, some risers have two holes and you should use the back one as a starting point which should be directly over the riser’s pivot point.

Pivot Point: The deepest part of the riser handle.

Alternatively, if your bow did not come with a threaded hole or you are using a traditional bow the arrow rest should be installed at the contact point of the arrow onto the rest directly above the “pivot point” of the bow. You may also want to investigate other types of arrow rests to match your style of bow.

Nock Pointing

Although some recurve archers use a tie-on nocking point, I recommend starting with a simple clamp-on type nock. Clamp-on style nocks are fairly easy to install and simply require your bow square and nocking pliers.

Nocking point: The location you attach your nock, it is usually measured 5mm (1/4”) above square from the center of the plunger and arrow rest.

measure-nockingAttach your bow square to the string so it is centered on the plunger ( or plunger hole) then measure up 5mm, attach a clamp-on nock, and secure it with nocking pliers. If your arrows are loose on your string, you can consider adding a nock serving for a better fit however once the nock is installed you can begin shooting.

Center-shot and the Plunger

For an Olympic archer the plunger (pressure button) is probably the best thing to attach to your bow for fine-tuning. The plunger can be adjusted to help match an archer’s release and counteract a lot of archer’s paradox. For a better understanding of arrow selection, center-shot and Archers Paradox check out my earlier blog.

To set your center-shot, set you plunger to the middle and install it in the threaded hole. Attach an arrow to the string, below the nock, and from behind the bow check to see if the tip is pointing slightly to the left (or right for left-handers).

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Although adjusting the plunger WILL require a trial and error approach, it is important to set the plunger to the middle position using the screw on the end. The amount of pressure setting for your plunger will depend on the archer, the limb poundage and your form. The best approach is to start with medium pressure and adjust accordingly after shooting a couple of arrows (Typically clockwise for more pressure and counter-clockwise for less).

Your bow should be basically setup and ready for you to focus on  developing consistent form. In upcoming blogs I will dive deeper into fine-tuning your bow.

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.

Arrows Series – Part 4: Spine, Flex and Stiffness

Before we discuss the topic of arrow spine, for proper safety and best performance, arrows need to match your entire bow setup. If you change draw weight, draw length, limbs, riser size, etc. this will affect you arrows. You may need to adjust the arrow length or require different arrows.

Arrow Myth:  An arrow is always straight.

Arrows SHOULD be perfectly straight when not in motion. However, when an arrow is released the force applied from the string causes the arrow shaft to be compressed against the resistant static weight of the arrow point and therefore bends.

Newton’s First Law of Motion: Every object in a state of uniform motion (rest) tends to remain in that state of motion (rest) unless an external force is applied to it.

Since the force applied is greater than the  resistance (weight of the tip), the arrow is propelled forward, and the shaft continues to flex and oscillate as it straightens itself. Arrow shafts that are either too stiff or too flexible will not fly well and will impact the accuracy of your shots or fail causing damage and/or injury. Therefore, we need to manage the flex properly so the arrow does not make any contact with the bow, or your arrow flight will be affected.

Important Tip: Arrow spine refers to the arrow shaft’s degree of stiffness (how much the arrow resists being bent) and is called spine deflection.

Basic Rule 1:  Shorter arrows act stiffer and longer arrows act more flexible.

Basic Rule 2: Powerful bows require stiffer arrows and less powerful bows require shafts that are more flexible.

Basic Rule 3: The heavier the tip equals greater the resistance, therefore the greater amount of compression.  So, a heavier tip causes the arrow to flex more and a lighter tip increase the stiffness.

According to the American Society for Testing and Materials (ASTM) the modern standards (ASTM F2031-05) an arrow’s official spine deflection is measured by hanging a 1.94 lb. weight in the center of a 28″ suspended section of the arrow shaft and is used for aluminum and carbon fiber arrows. (I believe original AMO standard has a basic guide to use for wood arrows spine determination and uses of 2 lb. and 26” section for standard measurement.) The actual distance the 1.94 lb. weight causes the shaft to sag down is the arrow’s actual spine deflection

For example, if a 1.94 lb. weight causes the center of a 28″ arrow to bend down 1/2 inch (.500″) the spine deflection would be .500″.  Stiffer arrows will bend less and more flexible arrows with bend more.

Almost every arrow manufacturer has its own numbering system and there are no universally agreed spine sizes among the various arrow manufacturers. Simply, the lower the deflection measurement equates to a stiffer arrow and higher the deflection measurement the more flexible the arrow. Manufacturers can number, size, and market their arrows anyway they want, as long as they provide the deflection data and test using the industry standard method.

Fortunately for us the engineers have already done the math for us and manufacturers provide spine selection charts. You are able to select an arrow based on your draw length and draw weight.

So when selecting arrows a good rule of thumb is that lighter draw weight, shorter draw length and/or lighter tip weight equals LESS arrow spine OR heavier draw weight, longer draw length and/or heavier tip weight equals MORE arrow spine.

Preparing to take on the World

The 2012 World Archery Indoor Championships in Las Vegas, Nevada are less than a month away, and I am equally excited and nervous. This will be my first experience at the World level and I am trilled about enjoying it with my junior recurve team mates, Virginie Chenier of Quebec and Caitlin Northey of Saskatchewan. I am sure that we will gel as a team however since we all live in various provinces we will develop our team round strategy at the hotel on practice days. Speaking of the Hotel, the South Point Hotel and Casino, where the event will be held, is located in the heart of the premiere southwest Las Vegas valley, just minutes away from the famous Las Vegas Strip. According to their website, some of their many amenities include a 16-screen Century Theatre movie complex, 64-lane bowling center and a handful of restaurants that cater to all appetites and tastes.  Their distinctive hotel features spacious rooms and suites with 42-inch plasma televisions, Point Plush mattresses and Wireless Fidelity throughout. A unique feature to this property is its Equestrian Center, which is the finest horse facility in the country. South Point also has a fabulous 400-seat showroom that features headliner entertainment and dancing to live bands on weekends. Although the hotel offers plenty to do, even for those under age of majority (21 in Nevada), I am not sure I will have a lot of time based on the posted schedule for the Championships. The practice venue will be open for both official arrival days, Friday and Saturday, and I plan to get there early on Saturday. The rest of the week looks like the following…

  • Day 1 Official Practice & Team Captain Meeting
  • Day 2 Qualification Rounds
  • Day 3 Individual Eliminations
  • Day 4 Team Eliminations
  • Day 5 Individual and Team Finals

Immediately following the championships from February 10th to 13th is the World Archery Festival, stage 2 of the Indoor Archery World Cup. However, due to the amount of school I would have to miss, I have decided not to participate, instead I will fly home on February 10th. I look forward to meeting so many new friends from all over the world, and participating in one of the archery world’s premier events. Until then, my focus will be on eliminating all distractions. First and foremost, finish this semester and exams the week before leaving. So rather than setting expectations to high; my goals are simple. First, focus on shooting and ignoring bells, whistles and the bright lights of Las Vegas. Then, give it my best effort each day, focusing on each shot and ignoring any mistakes. Lastly, learn and enjoy the complete experience. If all I bring back is the knowledge of what it takes to compete that the World level, I will succeed. I have been asked a couple of times now, however it is unknown at this time, if they will be streaming a live feed of the competition however results will be posted on the World Indoor website.