Understanding Barebow Nuts and Bolts

This is a follow-on article after “What Next for New Archers after Basic Course? – Part 1”. Most of it is authored by:

TOM BIL – Former Netherlands National Coach for Field and Disabled, National Coach Austria His contact details are: De Ruijterstraat 54, 3814 SL Amersfoort, The Netherlands
Tel: 00-31-(0)33-4722698; E-Mail: tombil@wxs.nl

The article is extracted from:

EQUIPMENT MODULE – BARE BOW – FITA LEVEL 2 MANUAL

FITA is now known as WORLD ARCHERY. Please visit World Archery Website for more information about the organisation.

The intention of this page is to provide the new archer with a detailed understanding of Barebow Archery. The illustrations may appear slightly dated but we find that many of the views and advice are still relevant; and important to the new archer. There is also good advice in equipment buying. We have focused on barebow issues as it is the primary interest of the Eagles of TBAC. Comments have been added to the article based on our experience, changes in equipment technology and regional archery trends, where relevant.

1. BARE BOW INTRODUCTION
The bare bow is defined, for competition, by FITA rules but can be seen as a bow that is shot without any extra equipment fitted e.g. sights or sight marks on the bow, draw check indicators etc. Archers who are planning/intending to shoot a bare bow have to consider the following aspects):
Bare bow is mostly shot in the FITA Field discipline / 3D / 3DI
Bare bow discipline is not Olympic
A lot of countries have a FITA indoor competition for bare bow. During the winter period there is a possibility of mail match for bare bow. Shooting a bare bow is a good start for beginning archers. Those who never had a bow in their hands, so far, will most probably draw the bow and aim over the arrow which is more accepted than using a sight.
When shooting bare bow after a while the archer will encounter problems concerning shooting the arrow and will notice there is more then just drawing, aiming and shooting the bow, especially at different distances, they cannot just adjust their sight. Bare bow archers develop a good feeling for their bows and can switch to recurve or compound bows later if they want to.
The method of shooting a bare bow is slowly getting accepted as a learning process for beginners.
It is a fact that bare bow archers have a very good “feeling” with their bow- and also, through experience, it is a fact that a bare bow archer can easily handle any other type of bow like the recurve or compound. A recurve or compound archer has far more difficulties changing to another discipline and type of bow.

It is not without reason that in some countries, like for example in Sweden, where beginners in archery shoot for the first few months with bare bows so that they learn every aspect of shooting with a feeling for the bow. After that introductory period they may make up their choice for any discipline they want to shoot.) It is recommended to start shooting with a bare bow so that the beginning archer gets to know all aspects of shooting especially the “feeling” aspects of shooting.

Comment: In the context of Singapore, barebow is now the prevailing platform for introducing archery to beginners. A lot of barebow archers also meddle around  very competently with Olympic Recurve and Compound Bows. Fortunately, we don’t have to remind them where their true passion lies.

2. THE BARE BOW AND ITS ACCESSORIES
If an archer has decided to go on with a bare bow and wants to buy his/her own equipment they should keep in mind that according to FITA rules the unbraced bow has to fit through a hole of 12.2 cm diameter, and that a riser of the shoot-through type is not allowed.

Several aspects should be considered in buying own equipment:
The draw weight of the bow should match the archer’s strength. A reasonable test for this is the following:
the archer draws his/her bow to anchor/aiming point and hold for 7 seconds, relax the bow rest it on his/her foot for 2 seconds repeat this at least 8 times with that short break in between.
If an archer starts trembling or does change body posture particularly of the shoulder girdle (for example gets a high bow shoulder or creeps forward with the drawing hand) before they reach the 8th time then a lighter draw weight is recommended. If all that does not happen during this test the draw weight is appropriate for that archer. If an archer could easily go on with further attempts a higher draw weight could be considered.
Comment: This is a physical means test that is often missed out by many. As a result, beginners and even experienced archers are over-bowed beyond their physical ability. This leads to poor archery form, performance and much frustration.

Bow riser/handle
All recurve bows are suitable, those of aluminium, magnesium or carbon are allowed (no shoot through types are allowed) as long as the unbraced bow fits through a ring of 12.2cm. The riser can be of every colour even camouflage, It is recommended that the sight window should be squared and high enough to help with “Gap shooting”.

It is not allowed to have any markings of any kind in the sight window.

Sight Picture
The lower part of the riser is recommended to be closed or if possible to apply the right amount of weight to tune the bow. There are some manufacturers, that make risers for or adjustable to bare bow shooting who supply weights that bolt into the holes in the lower part of the riser The effect is to cause the riser to naturally sit more vertical in the hand and to stop it “dancing” around when shot. Attaching extra weight on the bow is allowed. (provided they fit through the above mentioned ring together with the unbraced bow).

Riser

Stabilizers are not allowed, TFC’s without stabilizers may be mounted directly to the lower part of the riser. It is permitted to attach additional weights to the riser to provide for more stability on release; some bows have already built-in windings to fix such weights, others make it possible to wrap around metal bars.

Comment: Today, many riser companies produce dual purpose equipment suitable for barebow and Olympic recurve. Bernardini, Spigarelli, Gillo are some ……. to name a few. This market seems to be dominated by European makers, likely because there is a large following of barebow-olympic recurve cross-discipline archers in the Continent. Alternatively, one can affix customised riser weights (that comply with the relevant rules) to the riser bushings of most standard recurve risers.

Grip
As on all bows the grip is made standard and delivered by the manufacturer, which is not always the right form for the archers individually shaped hand. It is recommended that the archer resize the grip to their personal setting using either plaster or rasping/filing parts away or even make a new grip from wood according to their personal feelings. Size and shape of the archers hand, and the size and shape of the grip on the riser, will tell the archer to some extent where their personal hand position should be. It is permitted to change the shape of the handle to fit it better to the archer’s hand and personal way of gripping the handle.
Limbs
It is not allowed to have any markings of any kind on the front side (inside) of the limbs Limb savers are allowed. See FITA rule Book 4 Constitution and Rules art 9.3.3.1. for limb savers experts material art.9.3.3.7,.The bare bow limbs should be „stiff”, showing side stability, so that while shooting the arrow the bow will be more stable, stop it „dancing“ around on release. The following figure gives you an idea of the differences in limbs.

Limb Materials

Comment: Materials science has advanced substantially since Tom Bil first wrote this article.  Carbon-Foam in laminated or Full Carbon in moulded construction are now available. These are largely high performance  limbs with little stack effect but with prices to match.

String
All kinds of string material and colours are allowed. The centre serving should not be provided with markings. The archer could consider making it with a thicker thread so as string walking can be done thread by thread instead of using the tab; it depends what kind of nocking point they want to use.
Bear in mind that the lighter the serving the faster the string, and the heavier the serving the slower the string will travel, especially when using the double serving. The top end of the central serving should not exceed eye height (measuring aid). Thickness and number of strands also depends on what kind of nock the archer chose to use.
For example: some nocks have an inside diameter ranging from ø 2.0 mm (0, 0787 inch) up to ø 2,5mm (0, 0984 inch) Recommended are 14 to 18 strands (depending on the draw weight used).

Comment:  We recommend that you head straight for the modern low-creep string materials such as Dyneema, instead of Dacron. They are much more stable and less affected by changing weather conditions throughout a shooting day.
Arrow rest
There are various arrow rests, we mainly distinguish between stiff and moveable arrow rests:
when an arrow is released using fingers/tab the nock end of the arrow initially bends away from the bow. The nock end subsequently bends back towards the bow and then away again. Archer’s paradox is the term used to describe this bending behavior. The aim is to have the nock (fletching) end of the arrow bending away from the bow as it passes the body of the bow the purpose being to avoid any collision between the rear of the arrow and the bow.
We know from super slow motion pictures (Beiter) that the arrow actually is bent with the vertex away from the bow (nock and point towards the bow) as fletching and nock pass the arrow rest. And when the arrow has travelled forward just +/- 20cm it has a contact only to the string, the rest of it is completely free in the space. This way of moving is due to the fact that the energy transfer from the releasing hand to the string is coming slightly from the side and not directly from behind the arrow (as our fingers open “so slowly”); thus the string is describing a sinus-wave which the back end of the arrow is forced to follow. The front end with its rather “heavy” point gives resistance to the immediate flight forward, thus the bending of the arrow occurs.
It is to the archer (coach) to find that point either with a stiff or moveable rest.
With some of the arrow rests there could be a problem, it is recommended that the metal pin of the magnetic arrow rest where the arrow rests on should not be thicker then 1.5mm and +/- 3cm long. If it is not accordingly archer could have advantage on the 50 meter due to the fact that at long distances the finger are placed close to the arrow and the flight of the arrow leaving the string is a more “straight” line, and have more “clearance” while passing the Arrow rest (Archers paradox)and there is more time to compensate for a clearance problem. Whereas on the 5 and 10 meters the archer have a disadvantage due to the fact that archer’s fingers are placed very low on their string that scoring could not be possible because of the fact that the arrow “jumps” from their arrow rest, the thicker the pin less tolerance of arrow “jumping” and longer the pin more chance that their nock(fletching) make contact with the Arrow rest due to Archers paradox.
Also when looking from the top the end of the finger of the arrow rest should not be seen, as with a longer arrow rest clearance problems are very probable. With clearance problems archers grouping will be worse on shorter distances (like 30m) than on the longer ones (like 50m) it’s simply a problem for the arrow to find its proper trajectory within a shorter distance thus archer get poor grouping. On a longer distance there is more time to compensate for a clearance problem. The trick is that you have the arrow resting on the wire right in front of the plunger button and to cut off the unnecessary rest of the wire so that you can’t see it when looking from the top.
The above mentioned measurements for the pin is the recommendation gained through experience with elite Bare Bow archers.)

Magnetic Arrow Rest

Points to bear in mind are that the force exerted by the string on the arrow varies as the arrow moves forward and also that the direction of the string force is always towards the string bracing height position.
Use a strong arrow – rest. The arrow-rest the archer should use has to be reliably strong for string walking. Shooting with a gap of two inches and more between fingers causes a lot of down force on the rest. For example the Win & Win magnetic rest is a magnificent rest but flies to bits with extreme string walking.
The standard flip rests are robust enough.
Comment: A large number of robust magnetic flip rests are now available in the market, with model variations that can fit almost all riser designs. Popular and affordable rests are made by brands such as SF, Spigarelli etc. However, heavy stringwalking does tend to kick the launcher out of position. Compensating or adjusting the launcher arm geometry is a process of trial and error. It’s best to get some help from an experienced user/archer.
Button/Plunger
Every kind of adjustable button is allowed. However the pushing point of the button is not allowed to be placed further back than 20mm behind the grip–pivot point.
The pressure button is set up for a recurve bow so that the arrow at brace height is pointing left away from the bow (the off-centre position of the arrow) and the recommendation is that (for right-handed archers) the right edge of the arrow tip is just touching the left edge of the string when looking from behind with the string seen right in front of the (left-right) centre of the bow.

Comment: There is a very wide array of plungers in the market today. It is rather bewildering for beginner archers as the more sophisticated models come with indexed dials, springs of different tensions, tips of different materials, etc. The function of the button/plunger is largely to compensate for spine (arrow stiffness) and poor archer hand release. It’s advisable to get an inexpensive, simple, well built and reliable make such as the Shibuya DX until you figure out how much plunger tweaking you want do.
What initializes the Archer’s Paradox effect is the action of the fingers/tab on the bow string. At full draw the string force is balanced by an equal and opposite force on the tab. At the release the string force causes the tab to rotate as the fingers are ‘uncurled’ . At this point there are three forces acting, with the string force towards the bracing height position, the tab reaction force at a right angle to the tab surface and a tab frictional force parallel to the tab surface. These three forces add together to produce a net force on the string forwards and to the left away from the bow. The sideways acceleration of the string causes the arrow shaft to bend away from the bow at the nock and as a consequence the string force ends up running across the arrow shaft. At the same time the forwards acceleration of the string transfers the load from the tab onto the nock end of the arrow shaft.
As mentioned before in arrow rests we know from super slow motion pictures (Beiter) that the arrow actually is bent with the vertex away from the bow (nock and point towards the bow) as fletching and nock pass the arrow rest. And when the arrow has travelled forward just +/- 20cm it has a contact only to the string, the rest of it is completely free in the space. This way of moving is due to the fact that the energy transfer from the releasing hand to the string is coming slightly from the side and not directly from behind the arrow (as our fingers open “so slowly”); thus the string is describing a sinus-wave which the back end of the arrow is forced to follow. The front end with its rather “heavy” point gives resistance to the immediate flight forward, thus the bending of the arrow occurs

Archer's Paradox

An arrow must be spined correctly to oscillate at just the right frequency to “bend around” the bow. If it’s spine is too weak it will strike to the right of the target center. If it is too stiff it will strike to the left of the target center.
An arrow must be spined correctly to oscillate at just the right frequency to “bend around” the bow. If it’s spine is too weak it will strike to the right of the target center. If it is too stiff it will strike to the left of the target center.

Nocking point
Nocking points need consideration, especially if the archer makes use of the brass clamp type. When the arrow is shot from between the index and second finger (Mediterranean), the string stays more or less at right angles (assuming there is a half-way finger position, approximately 50% for each finger) to the shaft. When shooting three fingers under the arrow, at full draw, the string passes through the arrow nock at an angle. This means the string nocks have to be further apart to avoid pinching the arrow nock.
Nocking points of every kind are allowed- Beiter, Ambo or even a self made.
Beiter nock point has the advantage of a consistent thickness and a disadvantage while it tends to break and doesn’t fit to thicker strings of that kind of nock point.
AMBO Nocking Point have the advantage because the angle of the string to the arrow doesn’t play a role, disadvantage however is that the nock wings are rather wide apart and therefore can be damaged more easily through other arrows; also the double centre serving could be of disadvantage concerning the speed of travel of the string. AMBO Nocking Points and nocks are not easily to come by so when the archer buys Nocking Points and Nocks they should ensure themselves that they have enough for the future. AMBO Nocking Points centre hole varies from ø 2.0 mm (0,0787 inch) in up to ø 2,5mm (0,0984 inch) which will allow strings varying from 14 to 18 threads depending on the type and thickness of the string threads. Instructions on how to serve a Beiter or AMBO are included when you buy such a nock set.
It is recommended to have the same serving length as on the old string every time the archer makes a new string because of the trusted view. Without saying, all strings (one in use, two others for replacement) for an individual archer should have the same kind of serving, especially concerning length and thickness.
Remember the serving protects the string from contact with the tab and the arm guard. It also has an influence on the readings when tuning the bow, the lighter the serving the faster the string will travel, the weaker the arrow reacts (dynamic spine) and vice versa. A self-made nock point is a good and reliable alternative.

Comment: We have not come across anyone using the Ambo Nocks in Singapore. A visit to their website shows that the concept behind it is very sound. However, their nocks are only made to fit Easton shafts. Many high level archers use self made nocks without any apparent effect on their performance.
Arrows
Archer can shoot any kind of arrow with the bare bow but they have to be aware that they should be able to reach 50mtr butts under comfortable sighting conditions. With this in mind a male archer should at least have a 45 pound bow draw weight at 28 inch draw length. With ACC arrows the draw weight should be +/- 42 lbs, with ACE arrows +/- 35 lbs should be in order.
Comment: This was quite accurate, at the time of authorship. However, the availability faster limbs and lighter arrows means that 50m targets can be reached with reasonable accuracy with bow weights as low as 30lbs. One would expect 50m targets and beyond to become even more approachable in future, as material science develops further.

See the selection chart from EASTON or the “Shaft Selector Plus” or even the old Easton Arrow Flight Simulator for further references.
Also recommendable are the Red line and the ICS from Beman with a bow draw weight of +/-35 lbs. The Easton Navigator is a very good substitute for the ACE.
It is recommended for beginners to start off with arrows which are longer than the measured draw length, because the beginner has to learn to “feel” his draw length normally, after a few months of intense practising the draw length increases up to one inch or even more due to the strengthened muscles of the shoulder girdle and better use of their chest cavity through a good breathing. Accordingly, the arrows chosen should be one or even two spine values stiffer.
Tab
To anchor correctly on archers face he/she needs a flat tab (which is one without an anchor shelf).
To know where to place their fingers on the string according to the distance to be shot, it could be handy if the archers have stitches on their tab of about 3mm which compare a distance of approximately about 5 mtr. (3mm is reliable but mostly depends on the draw weight of the bow, the archer’s draw length, the weight of the arrow and the archer’s anatomy. The archers have to sort out this relationship for themselves under controlled conditions.)
There are also tabs with a height which the archer can fill up with anything they want and which allows them to have a lower anchor point and also have the anchor point on their cheekbone.
An anchor shelf tab is only suitable if the archer locates under his/her jaw bone. The purpose of a tab is to protect the fingers and to ensure a smooth uniform surface to effect a clean release A little talcum powder ensures a smooth surface, and extends the life of the tab. The purpose in having a smooth tab is that less friction of the tab makes the shot smoother. There is also an effect on the dynamic arrow spine; the smoother the tab the weaker the arrow reacts.
Finger tabs are preferable to shooting gloves as they present fewer fitting problems especially with string walking for exact positioning on the string. The tab should be big enough to cover the drawing fingers when bent to engage the string. Any surplus may be cut off. In contrary to the tab used in target archery the tab for bare bow archery consists of a smooth surface without a “cut in” for forefinger and second finger (Mediterranean) and without an anchor shelf. Compare: 9.3.8. of book 4 of FITA rules; a finger separator and a shelf are permitted.

Finger Tab 1

This type of tab comes in small, medium and large sizes for either right or left handed shooters

Finger Tab 2

This Tab is definitely a NO in field as it has extra markings on pad
– End of Article Extract
In the next instalment , we will talk about our approach and experience in equipment buying.

– Article compiled and edited by Tyger

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