Glossary of Terms for Archery

This post is intended to be an ongoing project (and is very far from complete at the moment!): a glossary of common archery terms with basic explanations.  If there are any terms you think should be added, let me know.

Parts of the Bow

Back:  the face of the bow that points away from the archer.  

Belly:  the face of the bow that points towards the archer.

Handle/grip: the part of the bow that is held by the hand.

Limb:  the section of the bow that is not the handle.  May consist of bending and non-bending parts.

Nock:  the point on the bow where the string attaches.  May consist of grooves cut into the side of the bow (usually both sides symmetrically but on some historical bows just one side); a groove in the back of the bow (usually on a static recurve) or a protrusion from the tip for the string to fit over, with shoulders to stop the string sliding down (this is sometimes known as a pin nock).  Not to be confused with the nock at the end of an arrow, the action of attaching the arrow to the string or the nocking point on the string.

Rest:  similar to a shelf but consisting of a piece of wood, leather, metal or some other material protruding from (and usually stuck to rather than made from the same piece as) the bow.

Shelf:  a section of the bow, often the bottom of a window, that provides a stable base for the arrow to rest on.

Siyah:  the stiffened tip of a static recurve.  Also known as the ear.

Window/cutout:  a section of the bow at the top of the handle that has been removed.  This serves two major purposes: it makes the bow more centreshot and it provides a shelf.

 

Strings – Parts and Manufacture

Loops:  the loops at the end of the string, that fit over the end of the bow.

Nocking Point:  the point on the string where the arrow attaches.  It is important to get this position right, for optimum arrow flight and to reduce the risk of the feathers’ cutting the hand.  Nocking point also refers to a marker attached to the string to mark this point.  They often consist of small brass “U” shaped pieces that are clamped around the string but it is better to use a piece of dental floss or similar wrapping (since this is lighter and therefore allows faster string movement, as well as not cutting the drawing fingers as brass can do.

Serving:  any of various types of thread wrapped around the string.  Centre serving is the section of thread wrapped around that part of the string where the arrow will attach.  It allows the string to be built up to a thickness appropriate to the arrow without needing to have the whole string that thick (and therefore heavy and slow).  It also protects the string from friction from the arrow.  End serving, also known as loop serving is the thread wrapped around the loops.  It protects the loops from friction and also ensures that the loops stay closed.

 

Arrow Speed – Graphic Predictions

In my last post I wrote about the testing of my various arrow through my shiny new chronograph.  Since then I have bought two different types of all carbon shaft to try: Easton Apollo 560 and Easton PowerFlight 500.  For the PowerFlights I have a choice of points: 60gn or 100gn points (the Apollos have 100gn points).  Is it possible to predict the speed of these arrows?  Since I have had a flare-up of an old back injury and for the last 48 hours haven’t been able to stand upright or walk without a limp (and ideally a stick) I am going to attempt to do exactly that.

The first big caveat is the one pointed out by Steve Ruis in his comment to my last post: correct arrow spine is critical to speed.  In particular, dynamic spine is important.  As regular readers will know, this is the extent to which the arrow bends as it is shot, as opposed to static spine, which is how much it bends when a weight is suspended from it at rest.  These three variants (Apollo, PF with 60gn and PF with 100gn) are going to have different dynamic spines.  The Apollo, as a .560 spine, is weaker in static spine than the .500 PFs (I am going by the marked spine for these purposes).  With their 100gn points they are likely to remain weaker than the PFs.  The PFs have the same static spine (being identical shafts) but the 100gn points make the dynamic spine weaker than the 60gn points do.  This may well have an effect on speed.  I shall be able to correct for this factor to a limited extent by shooting each variant as a bareshaft first (I am also going to do this with the other arrow types I tested in the previous article).  Having shot the Apollo bareshaft already, I can say that they are a touch weak but not too bad.  They are stiffer than most of the aluminium arrows I tested in the last article (though not than the A/C/Cs, which might explain that arrow’s slightly high performance).

Leaving spine hypothetically to one side, what predictions can we make?  Well, the new arrows weigh as follows (+/- 0.5gn):

Apollo: 360gn

PF w/100gn: 350gn

PF w/60gn: 310gn

We would therefore predict that they would all fly faster than even the fastest (and lightest) of the arrows in other test (which weighed 372gn).  We would expect the PowerFlights to be faster still, with the 60gn tips being fastest (subject, as I say, to the effect of spine).

What is the relationship between mass and speed?  Applying our favourite formula, F=ma, we should expect a linear relationship.  That is to say, since a=F/m, where F is a constant (the stored energy in the bow), we should expect speed to rise in inverse proportion to the drop in arrow mass.  Note that this does not mean that if we half arrow mass we double arrow speed.  The mass that is being propelled by the bow includes the mass of the bow’s limbs and the string.  With that clarification in mind, however, we should expect to see a straight line if anybody were to be sad and geeky enough to draw a graph of arrow mass against arrow speed.  Like the one below, for example.

Arrow speed graph

As you can see, the arrows I tested last time form a straight line, subject to some pretty sizable error bars caused by poor shooting form, variations in spine etc.

I have added dotted lines to represent the three new arrow variants that I intend to shoot in the next few days.  The prediction from the graph (apologies for the unclear numbers on the y-axis: it was late when I drew this graph) is that the Apollos will fly at 192fps, the PF with 100gn points will go at just under 195fps and the PFs with 60gn points will be around 204fps.

As you will have gathered from the various caveats (variations in spine; less than perfect consistency in my shooting technique; differing nocks; drawing a graph at midnight in a childrens’ drawing pad etc) mean that this is not exactly perfect science.  I am not, as one should do, isolating one variable.  My prediction, however, is that factors such as spine difference will not affect the speeds to an extent that trumps weight.  I expect to see the order of speeds as predicted and I do not think that the actual speeds will be out by more than about 5fps.

And as soon as my back heals, I shall test it and let you know!

My New Chronograph

I have just bought myself a chronograph.  Specifically, a Chrony F1 with lighting set.  The lights let you use it indoors but I have no intention of so doing.  It’s just that it was on sale and getting it with lights worked out cheaper than getting it without.

For those who don’t know, a chronograph is a device for measuring the speed of an arrow (or bullet, pellet, paintball etc).  It’s basically a long box with a laser at each end that beams upwards.  It starts an internal stopwatch as the front of the arrow goes through the first beam and stops it as it goes through the second beam.  Using the recorded time and the distance between the beams, it works out the speed of the arrow.  This is a brilliantly useful tool: every time you change something – fletchings, brace height, string material, arrow shaft etc – you can shoot before and after through the chrono and see what effect the change has on your arrow speed (and therefore on your trajectory and point of aim: see earlier posts on arrow speed).  I explained all this to Claire, my loving and long-suffering wife.  She replied “you want it because you’re an archery geek and it’s a cool new toy”.  She was, of course, entirely right; but it is also a really useful piece of kit.

image

The chronograph is famous among archers for its disappointments.  We all expect our favourite bow to be whipping arrows out at 200 fps or faster.  Then we get to a chronograph and discover that we are barely touching 180.  Like all good science, it can be a cruel destroyer of our cherished illusions, but one that should lead us to make informed changes to improve our situation.

Today the chrono arrived and I took it down the woods for a play, together with my Border Ghillie Dhu and a variety of arrows to test.  I ended up comparing the following (all made by Easton and listed: type; spine; mass in grains; grains per pound of draw weight (gpp)):
XX75 Platinum Plus; 2016; 431gn; 11.65gpp
XX75 Tribute; 2016; 429gn; 11.59gpp
X7 Eclipse; 2014; 372gn; 10.05gpp
X7 Eclipse; 2114; 390gn; 10.54gpp
A/C/C; 3-39; 384gn; 10.38gpp

Note: I have assumed for these purposes that I was drawing 37lbs.  This is the marked weight of the bow at 28″.  I did not measure the draw weight or my draw length for these purposes, since the aim was to compare arrows rather than necessarily give accurate gpp readings.

Judging purely by arrow mass, therefore, we would expect the Platinum Plus and the Tribute to be of similar speed, with the Tributes maybe a tiny bit faster.  We would then expect the 2114 Eclipse to be faster than those two, with the 2014 faster still.  We would expect the A/C/C to be somewhere between the two sizes of Eclipse.  Sounding a note of caution here, I will say that I had limited numbers of the X7 Eclipses and had a few error readings (basically I missed the beam).  This means that the speeds for the X7s may be less reliable than the others.

There are other variables beside mass.  One is the nocks.  Nocks can be tremendously important to arrow speed.  The nocks on all of these arrows were the same, except for the A/C/C, which has a rather better (and more expensive) nock.  The remainder all used the same nocks.  The situation is complicated a little by the fact that the nocks on the aluminium arrows (i.e. all except the A/C/C) have been splayed and this can mean that they vary slightly in fit.  We shall keep this at the back of our minds while remembering that I shot at least 3 of each type of arrow and then took an average, which should mean that differences in nock splaying cancel each other out.

Air resistance can be a big factor in arrow speed.  It is determined by a variety of factors including thickness or shaft and size/setup of fletchings.  The aluminium shafts all have the same fletching but in any event we would not expect resistance to make a significant difference at the short range here (I was standing about 3ft from the chronograph).

The average speed of the arrows is noted below (in feet per second):
Platinum Plus: 173.53 fps
Tribute: 177.59 fps
2014 Eclipse : 188.16 fps
2114 Eclipse : 182.38 fps
A/C/C: 194.42 fps

As we expected, then, the Tribute marginally outshoot the PP.  Both are outshot by the  Eclipses, with the lighter Eclipse faster than the heavier one.  The anomaly is the A/C/C.  This went faster than expected from the simple masses.  One explanation may be the nocks.  Another can be seen when the raw data is examined.  On one shot I really went for it, nailing the release, pushing the bow hand forward and probably drawing quite a bit further than usual.  The result was an arrow that went at 208 fps!  If you remove that arrow and stick with a fair comparison of regular draws, the A/C/Cs drop to 187.65, which is in the expected range, slightly higher than we might expect, but that’s likely to be the nocks.  This removal of the faster arrow is not some form of special pleading, by the way: it is perfectly sound to remove an anomalous result from a set of statistics.  This result varied from the mean by more than twice what any other arrow did and produced a result at odds with all of the rest of the data.  Keeping it in would be poor science.

The final adjusted results, therefore, are:
XX75 Platinum Plus; 11.65 gpp: 173.53 fps
XX75 Tribute; 11.59 gpp: 177.59 fps
2114 X7 Eclipse; 10.54 gpp: 182.38 fps
4/40 A/C/C; 10.38 gpp: 187.65 fps
2014 X7 Eclipse; 10.05 gpp: 188.16 fps

This is in accordance with our expectations of reduced mass bringing greater speed.  What lessons have I learned?  Well, for starters I shall stop buying Platinum Plus and go back to Tributes as my basic arrow.  I shall also look at investing in another set of X7s.  Quicks Archery very kindly sponsored me and Claire by giving us reduced rates on X7s before Korea last year.  These have gradually vanished into the undergrowth or been bent around trees or target frames and the time has clearly come to replace them!

I do not claim that this is anything approaching a perfect experiment.  There are various things that should be (and will be) addressed.  One is shooting more arrows so as to get a better idea of the average speed.  Another is getting somebody else to shoot it, to try to obviate any unconscious bias (although I did this to some extent by not weighing the arrows until after I had shot).  My draw length is not as consistent as it should be, although this should have evened out between the different arrows.

This is the first in what will be an ongoing series of articles where I get to play with the chronograph.  I shall set out more detailed and scientific findings in future posts, in which I hope to deal not just with the effect of changing other variables such as brace height but also to try a variety of bows and do some kind of comparison (I am intrigued by the number of relatively inexpensive bows out there that advertise speeds over 200 fps without giving a draw length, draw weight, arrow weight etc.  After reading this post, I hope that you will share my cynicism of such claims).

Theory Into Practice – Tuning Your Arrows and Bow

Enough theory, let’s talk about practicalities.  I’m working on the basis that you have your bow and are selecting a new set of arrows.  To do this you will need to go through a process called bareshaft tuning.  I suggest reading the whole of this post before starting.

You will need a selection of arrows of varying spines.  Some shops will do a set of shafts of varying spines for you to try bareshaft tuning your bow.  If you can find such a deal then great.  If not then your best bet may well be to use wooden arrows for tuning, since they are likely to be cheaper than modern materials.  If you are using wood then I recommend screw-fit points.  This is because you will be removing the point and shortening the arrow, which with regular points means cutting the point off and sticking a new one on.  You might get through a lot of points!

Your starting point is a spine selection chart.  There are loads of them online (just google “arrow spine chart”), some for woods and some for carbon/aluminium.  They are fairly self-explanatory: you cross-reference your bow’s draw weight and your arrow length to get a spine value for your arrows.  This is a starting point only.  If offered a choice of bow types, I suggest using “longbow”, but perhaps selecting a draw weight that is slightly higher than your actual draw (5lbs or so).  This will depend on your bow’s performance.  A really fast Saluki will need stiffer arrows than a budget bow from eBay of the same draw weight.

Bareshaft Tuning

As I explained last time, arrows of the wrong spine will not fly straight.  This is why we use fletching.  Fletchings are great.  They stabilise your arrows and can iron out a lot of problems with spine and arrow flight.  They do this by imparting drag to the back of the arrow.  The bigger the fletchings, the quicker and more effectively they will straighten the arrow.  The downside is that by imparting drag they slow the arrow down, with all the problems that I discussed when dealing with arrow speed in an earlier post.  The less well spined the arrows are, the more time the fletchings will spend side-on to the air, which means the more they will slow the arrow down.  Perfectly spined arrows do not need such big fletchings and such fletchings as they do have will not slow the arrow as much as the same fletchings on badly spined arrows.  Bareshaft tuning involves shooting unfletched arrows to see how well the arrow is matched to the bow.

Standing about 20ft (7m) from the target (ideally a soft “bag” style target), shoot an overlength bareshaft into the target.  It is best to do this with two or three arrows to ensure that any results are not the result of poor technique on a particular shot (if you have poor technique on all your shots then that’s a quite different problem!).  Now examine the arrows in the target.  In particular, look at the alignment of nock and point, as seen along the line from where you shot.

Interpretation

The interpretation of the arrows depends on how you are shooting.  I am going to set it out for a right handed archer using a thumb release, i.e. with the arrow on the right of the bow from the archer’s point of view.  The same conclusions will apply to a left handed archer using a Mediterranean release.  For a right handed Mediterranean release or a left handed thumb release you need to reverse whatever I write here.

If the arrow hits the target “nock left”, which means that the nock is significantly to the left of the point, then the spine is too strong – the arrow is not bendy enough.  Bearing in mind that the bareshaft is too long, you will not be able to get it to shoot properly from your bow.  You should discard it and try weaker arrows.

If the arrow hits “nock right” then it is too weak.  This is what we are hoping for because it is too long and, as discussed last time, the dynamic spine will get stronger as the arrow is shortened.

Assuming that you are getting a nock right impact, you should now remove the point and shorten the shaft by ½” or so.  Reattach the point and shoot it again.  The arrow should now be slightly less nock right.  Remove the point and shorten it again.  Then shoot again and so on.  BE CAREFUL NOT TO SHORTEN THE ARROW BEYOND YOUR DRAW LENGTH!

Your arrow spine is right when the bare shaft is hitting dead straight.  If it gets there too soon (i.e. your arrow is still far too long) then the arrow is too stiff.  If it is still nock right when you reach your minimum length then the arrow is too weak.  In either case you either need to get new shafts or you can try to make adjustments to your point weight or brace height.

Brace Height and Point Mass

Ideally you should not make significant changes to these factors, since they will both have other effects.  Relatively minor changes can be useful for fine tuning.

For reasons discussed in previous articles, a lower brace height will put more energy into the shot.  This means that the arrow will bend more.  In other words, a lower brace height effectively weakens the dynamic spine of the arrow.  Now, you probably don’t want to make more than a minor adjustment to the brace height (1/2” is plenty).  This is a matter of fine tuning.

In addition, brace height changes affect other things about the bow.  I once had a student shooting a Grozer biocomposite static recurve.  It twanged loudly and felt like it was shaking your fillings out when you shot it.  I changed the brace height by ¾” and suddenly the bow shot almost silently and with very little handshock.  If you change your brace height as part of bareshaft tuning, therefore, you must remain aware of these possible side effects.  It may be better to change the arrows rather than the brace height.

The other piece of fine tuning that you can do is changing the point mass.  A heavier point effectively weakens dynamic spine.  A lighter point strengthens it.  Again, however, changing the arrow mass affects flight.  In particular, raising arrow mass decreases arrow speed, so don’t go overboard.  For normal bows in the range of 30-50lbs you will probably want to shoot 100-150gn points.  Lighter is better than heavier, generally speaking.

Bareshaft and Feathered Together

If you already have some fletched arrows that fly tolerably well then you should include these in your bareshafting.  Just mix them in with the bareshafts and shoot them all the same way at the same point on the target.  The fletched arrows can be taken as a control group: the bareshafts should hit to the left of the fletched arrows if the bareshafts are too weakly spined and to the right if too stiff (again, assuming a right handed thumb shooter or left handed Mediterranean shooter).  If you find that this method is giving you different results from the bareshaft angle (e.g. the bareshafts are hitting left of the fletched arrows but are doing so with a “nock left” impact) then the problem is your shooting form and you should be wary of making and adjustments until you are getting consistent results.  If your existing arrows are not spined to the bow then this method is of much less use.

Nocking Point Height

If you nock too high or too low on the string then you will get poor arrow flight and quite possibly cut your hand on the quill of the feather.  Bareshafting can be used to get your nocking point height right.  To set nocking point height properly, you should start with it obviously too high and shoot at the target.  It will impact “nock high”.  Now lower the nocking point by 1/4” or so and repeat the shot.  The arrow should be slightly less nock high.  Repeat this process until the arrow flies straight.

The reason for starting too high is so that you know whether you are high or low.  If you start about where you think it should go then you will not know whether to adjust it up or down.  Contrary to popular theory, a nocking point that is too low will generally give you a nock high impact because the nock end of the arrow is pushed up as it passes over your hand.  If you start too high then all adjustments will be downwards, so long as you only move it a little each time.

That’s It!

If you have read this and my other posts on bow mechanics and arrow dynamics then you will now know all you need to know to set your equipment up properly for maximum efficiency.  Please do take the time to select, tune and care for your equipment.  Even if horsemanship is more important, the archery side of this sport should not be ignored.

As ever, please do post any comments, questions or observations.  I’ve finished with technical stuff for a while.  Now for something completely different…

Arrow Spine: Determining Factors

Now that we have established what spine does, you need to know how to change it. The following factors affect the spine of arrows:

    Shaft Stiffness (Spine)

There are far too many possible jokes for me to bother making any.

Fairly obviously, the most important factor in determining how much an arrow bends is how bendy the arrow shaft is. This will be determined by the material and the thickness of the shaft. The bendiness of the shaft is generally referred to as its spine, but it is important to remember that it is not the whole story. I tend to think of the bendiness of the shaft as “arrow spine” or “static spine”, as opposed to “dynamic spine”, to which we are coming.

Arrow spine is measured in pounds of draw weight but I hope that by now you realise that draw weight is not the only factor. If you have not grasped this point, you might like to read my earlier posts on bow mechanics. Arrow shafts are sold by spine weight, usually in bands of about 5lbs. For wooden shafts you will simply see a box labelled “35-40” or similar. Carbon and aluminium shafts have a slightly odd system of coding, unique to the type of shaft, which tells you the wall thickness, diameter and mass per inch, as well as shaft spine. There are tables, known as spine charts or spine tables that will help you to find the right shaft.

For a given shaft spine, however, you can make the arrow more or less stiff by adjusting the following factors. They all affect how much the arrow flexes when subjected to the force of the bow’s shot. This is sometimes called dynamic spine (i.e. spine when moving).

    Length

Longer arrows are more flexible. Take a long stick and waggle it. Then snap off a 6″ section and try to waggle that. See?

In addition, a longer arrow should denote a longer draw length (you should not have a large amount of arrow sticking out in front of the bow at full draw) and longer draw length means more stored energy and, all else being equal, more force on the arrow, resulting in more bend.

Having said that you should not have a lot of arrow sticking forward, there is nothing wrong with a couple of inches. Leaving the arrows a bit long may therefore be used to lower the spine of the arrow.

    Point Mass

Heavier points make at arrows bend more. When the bow first applies force to the back of the arrow it will bend the shaft until enough force travels up to the point to move the point which, being heavier, needs more force to move. The heavier the point, the harder it is to move and so the more the shaft bends before it moves the point. Put another way, take a stick and waggle it, then attach a weight to the end and waggle again. See?

    Brace Height

Lower brace heights increase the length of the power stroke, thereby increasing the amount of energy available for pushing the arrow. This makes it bend more. Take that stick again and waggle it. Now waggle it harder. See? The same applies to string mass: it changes the force applied to the arrow.

    Overall Adjustment

It is possible, by means of changing length and point mass and brace height, to change the dynamic spine of an arrow quite considerably. Don’t.

Changing your point mass or arrow length affects arrow mass as well as spine. Point mass will also affect something called FOC, which is the proportion of arrow mass that is in front of the middle of the shaft’s length. This affects flight characteristics. Changing your brace height will change the energy available to the arrow and can produce handshock, poor arrow flight and so on.

What you should do is brace your bow at the correct height as recommended by the bowyer, then select the correct arrow spine. Get your arrows about 4″ too long. This gives you a decent starting point for bareshaft tuning, which is what we shall cover next time. Point weight, arrow length, brace height and string mass should be thought of as things you have to keep constant in order to maintain consistent spine once you have found it. In selecting and tuning your arrows in the first place, they are for fine adjustments, not major changes.

Arrow Spine and the Archer’s Paradox

We have come at last to arrow spine and the archer’s paradox. Let us examine the paradox first.

    The Archer’s Paradox

This is a much misunderstood phrase. The “paradox” is that if an archer wants to hit a target then the one thing he should not do is line up the arrow with the target. This was noted in the days before centreshot bows and mechanical releases, which minimise the archer’s paradox. As usual, I shall ignore such matters and assume a regular horsebow.

It is easiest, while I explain the paradox, if you imagine holding a bow vertically with an arrow nocked (or even get your bow out and try it). If you hold your bow so that the string and the handle line up with the target then before you draw the bow back the arrow sticks out to one side. It cannot point at the target because the handle is in the way. When you draw the bow this effect becomes less marked, simply because the nock is moving further from the handle and the point is moving closer to it. The angle is still there, however. If the string is released and returns to brace height then a perfectly rigid arrow would not be propelled directly towards the target.

    Spine

The reason we can hit the target is that arrows are not perfectly rigid. They flex when force is applied. They actually flex quite a lot. If you get the chance, I recommend looking on YouTube for high speed footage of the archer’s paradox. Beiter have some excellent clips.

The fine detail is not terribly important, but basically what happens is that as you release, the string does not go in a straight line to brace height. It rolls off the tip of your fingers/thumb, which has the effect of moving the arrow’s nock end laterally away from the bow (this is easy to visualise if you think about the release). The string is also moving forwards and the effect is to bend the arrow and propel it forwards. The string is now moving on slight angle because it is returning to brace but has been moved to the side on release. This, together with the fact that arrows don’t like being bent, causes the arrow to flex back the other way as it is driven forwards. On release it will continue to flex as it flies, although various factors will help it to straighten out more quickly, notably drag at the nock end caused by the fletchings.

This is where the magic of spine becomes really useful: if we select our arrows to bend exactly the right amount on release then it will bend around the bow’s handle and fly directly at the target.

The next couple of articles will be about spine. The first will deal with the factors that affect spine and the one after it will be on how to test and adjust spine.

One important point before I move on to those topics, however, is that the most important thing is that all your arrows should match. They should be of the same mass and the same spine. That way at least you can shoot one and know where the others will go. If your arrows are of different mass and spine then you cannot know where to aim because you cannot know how each arrow will act. It is better to have all your arrows slightly wrong than some right and some wrong. How close they have to be to each other is a matter of personal tolerance. Personally, I ensure that all of my arrows are within 5gn of each other in mass and within 5lbs of each other in spine.

Next time, we shall look at the various factors that impact on the spine of an arrow.

Bow Mechanics 3: String Theory

Yes, I know I said that the next post would be about arrows but you shouldn’t believe everything you read online.  I want to deal briefly with strings before moving on to arrows.

First and most importantly, you must check with your bowyer before you change your string.  Use of an unsuitable string can break your bow beyond repair.  Be warned!

There are many different kinds of string.  In particular, there are various string materials and two main ways of turning the threads into a bow string.  I am not going to go into much depth but I want to discuss two main features of strings that can affect performance: stretch and mass.

String Stretch

You might think that a nice elastic (stretchy) string would give some extra pace to the arrow.  You’d be wrong.  If you use an elastic string then at the end of the power stroke it doesn’t stop dead, leaving the arrow to fly off.  Instead, the string slows down as it stretches.  By the time the arrow flies off it has lost some of its speed.

Studies in fact show that the various modern materials are unlikely to differ enough in their stretch to make a significant difference to arrow speed.  Materials such as B50, Dacron, FastFlight etc have different elasticity but they are close enough that the difference in arrow speed from stretch will be no more than 1 or 2 feet per second (fps).  This is about the same as increasing your draw weight by 1 or 2 pounds.

The way the string is put together will also affect stretch.  There are two basic methods of making a string: Flemish splice (also known as laid in) and endless loop.  You don’t need to know the technical differences but it is worth knowing which you have.  As a general rule, Flemish splice strings have slightly more stretch to them.  Endless loops have higher performance: they don’t stretch as much and they can be made identical more easily than Flemish strings (allowing you to maintain performance the same with spare strings).  The Flemish splice string will also “creep” more.  This means that once the bow is braced the string will stretch so that it becomes slightly longer.  This, of course, lowers your brace height over time, making consistency harder to achieve.

So why would anyone choose a more elastic string than necessary?  Because they are more forgiving on the bow.  At the moment that the string snaps taut there is an awful lot of force going through the tips of the limbs where the string attaches.  If there is no ‘give’ in the string then weaker tips will break at this point.  This is the main reason why you should check with your bowyer before using a new type of string.  In particular, bows made from traditional materials such as horn, wood and sinew may well not be able to cope with modern low-stretch strings.

String Mass

String mass generally has a greater impact on performance than stretch.  A high-performance string material such as FastFlight or Dyneema weighs much less than something like Dacron (which is what most “off-the-shelf” strings are made of).  To take an example, I have in front of me two strings.  One is a Dacron string that weighs (including the serving) 151gn.  The other is FastFlight and weighs 63gn.

So what?  Well, the string, like the arrow, is a mass that needs to be driven forwards by the bow’s stored energy.  The heavier the string, the slower the arrow will be.  According the Traditional Bowyer’s Bible, Vol.1 (which admittedly deals primarily with straight limbed wooden bows), a 20gn increase in string mass will slow the arrow by roughly 1fps for a bow of around 50lbs draw weight.  The effect is greater on lighter bows (because a greater percentage of the stored energy is needed to move the string).

This assumes that the added string mass is evenly spread.  Mass added to the centre of the string has about 3 times the effect (as does mass added to the arrow, but we’ll come to that in a later post).  Those little brass nocking points clamped to your string weigh 5gn each.  If you have two of them on your string and are shooting a relatively light bow then you could be losing about 2fps just from them.

All this may not seem very much but there are good reasons to get it right.  One is that the string is the cheapest way to gain arrow speed.  Bows and arrows are expensive but a decent string is not.  If you can reduce your string mass by 100gn (which you could easily do if your current string is one of the big heavy horrors that you sometimes find) and replace your brass nocking points with a dental floss wrap or similar then you can make considerable gains in arrow speed.  Further gains can be made with your arrows, to which I shall turn next.

Bow Mechanics 2: The Return of the String

So there you are at full draw, all that stored energy literally at your fingertips (unless you’re using a thumb draw); all that’s left is to let fly. Let’s take a look at the mechanics of what happens when you release the string. As before, I shall simplify some elements of the discussion, removing some complications such as energy lost to internal friction, heat and sound. Some of what I write will therefore not be technically accurate, but the principles are sound.

What happens on releasing the string is that the stored energy drives the limbs forward until they return to brace height, at which point the string snaps taut. String and limbs suddenly stop moving but the arrow keeps going at the same speed. Factors such as the elasticity of the string may complicate this picture slightly but I shall address that in a later post. For now we will assume that at the moment the bow reaches brace height the arrow flies off at the same speed as the string was moving a moment earlier.

Once we understand this point about the way an arrow leaves the string we are in a position to understand that if we want fast arrow speed then we need fast string speed. That follows from fast limb speed. The question is therefore how to get fast limb speed.

    Dry Fire Speed

Every archer dreads the moment some non-archer asks to try pulling their bow. “OK, but don’t let go of the string!”. Lesson 1 of archery: do not dry fire your bow. Why? Put simply, if you dry fire your bow then the energy stored in the limbs has nowhere to go. It stays in the limbs, which are not built to withstand the shock.

There is one thing to know about dry firing, apart from “don’t”: it is the fastest speed at which your limbs will move. A bow drawn and released will shoot at dry fire speed (which varies with draw length for a given bow) unless it is slowed by the mass of the arrow.

    What Determines Dry Fire Speed?

A bow’s dry fire speed is determined by the bow’s construction and the amount of energy stored in it. Energy storage was covered in my last post and I shall not go over it again here.

Bow construction also has a great effect on stored energy but in addition to this it affects the dry fire speed of the limbs for a given amount of stored energy. The main factor I shall examine here is mass. Other factors have an effect but mass is the most important one.

    Limb Mass

Sir Isaac Newton showed that Force = mass x acceleration. It follows that acceleration = force/mass. In other words, for a given amount of stored energy you will get higher dry fire speed from lighter limbs than you will from heavy limbs.

The placement of the mass is also important. The bow limb can be likened to a lever. Mass at the end of the limbs requires more energy to move than mass near the handle. Studies reported in the Traditional Bowyer’s Bible show that adding 1oz to the grip section did not slow the limbs at all, whereas adding 1oz to each limb tip slowed the bow by around 7 feet per second (fps). This is roughly equivalent to shooting an otherwise identical bow that is 7lbs lighter in terms of draw weight.

Many horsebows have siyahs: rigid recurved tips. These increase stored energy (by raising early draw weight and removing stack) but if they are too massive then they will slow limb speed. We will see below that slow limb speed combined with high energy requires a heavy arrow to avoid excessive handshock. This is because of kinetic energy.

    Kinetic Energy

Kinetic energy is the term used for the energy related to movement. Its equation is KE = 1/2mv2. In other words, kinetic energy is equal to the mass of an object multiplied by the square of its velocity (speed), all divided by 2.

When a drawn bow returns to brace height it will have no stored energy. All the energy it had stored has become kinetic energy. As the string slams taut that kinetic energy has to go somewhere. It goes into vibration of the limbs, the string, the archer (handshock) and the air (noise). There is one other place it can go: the arrow.

    The Arrow

As the string travels along the power stroke we should consider the bow and arrow as a single entity whose stored energy is being converted into kinetic energy. At the end of the power stroke there is no stored energy available – it has all become kinetic energy, shared between the bow and arrow.

At the end of the power stroke the arrow leaves the string at the final speed of the string. Since the arrow has a known mass we could calculate its kinetic energy. Without needing to do this, however, we can already see that at a given speed the arrow will have more kinetic energy if it is heavier.

We have now gone from having a total kinetic energy for the bow and arrow to having an arrow with kinetic energy and a bow that has stopped moving and therefore has no kinetic energy. Nor does it have stored energy. Any kinetic energy that has not gone into the arrow becomes vibration.

    Vibration

There will always be some vibration after the arrow flies off. The string and limbs will vibrate. This is not a problem if it is kept to a relatively low level. Nor is the noise of the string twanging, which is just the vibration going into the air.

If too much energy is left in the limbs then they vibrate too much and you feel it as handshock. In extreme cases the bow can be damaged or destroyed. This is why you should not dry-fire you bow: all the stored energy ends up as vibration.

To hunters and warriors the kinetic energy of the arrow is important: it plays a major role in determining the penetration of the arrow into the target. For a sportsman trying to obtain fast arrows the kinetic energy of the arrow is of less importance, save for this basic fact: arrows that are too heavy will slow the string too much and therefore travel too slowly. Arrows that are too light will not absorb enough energy from the bow, leaving too much energy in the limbs, which will vibrate the bow and your arm.

    What Does All This Mean?

There is a balance to be drawn when selecting your bow. Static recurves (those with recurved limb tips that do not straighten as the bow is drawn) store more energy than equivalent straight bows or working recurves (those that straighten as the bow is drawn). If those recurved limb tips are too massive, however, then even the extra stored energy will not be sufficient to move the limbs quickly.

This is especially true at low-medium draw weights. High energy/high mass bows are good for shooting at heavy draw weights and for shooting heavy arrows because they store a lot of energy but they are not so good for producing really high arrow speeds with low draw weights and light arrows. There is a reason why bows like the big Mongol recurves and the English longbow were used at draw weights of 150+lbs. The English war arrows weighed up to 1/4lb!

The ideal compromise is probably a bow that has static or partially static recurves but whose recurves are of low mass. The best examples that I have seen (and I do not pretend to have seen all available bows) are Saluki bows made by Lukas Novotny. They are of low mass but maintain their recurves for high energy storage. The resultant arrow speed is phenomenal.

So there you are: your arrow is on its way. In my next post I shall look at the way arrows fly, examining arrow mass and spine and how to get them right for your bow.

Bow Mechanics – Energy Storage

It is commonly said that the most important part of horseback archery is the partnership between rider and horse. Many thousands of words have been written and typed on this point, covering the technical and spiritual sides of becoming one with the horse. I do not pretend to be a good enough horseback archer or a good enough horseman to assess whether this is true. Far better men and women than I have asserted it and I will not argue.

Without arguing against horsemanship, I want to put in a word for archery, and in particular for archery equipment. Many people could, I believe, improve their performance greatly by understanding how their equipment works and treating it properly. The bow may not be as important as the horse and it certainly doesn’t take as long to master as riding does, but it is important nonetheless, and its simplicity should make it something that everybody understands rather than something that is overlooked.

I am therefore going to write a series of posts about the mechanics of bows and arrows. I shall start with bows and how they work. After going through this I shall move on to consider arrows. I happen to believe that arrows are more important than bows but it is impossible to understand arrows until you understand bows, so I shall start there. A word of warning: this post is fairly long and fairly technical. It contains some simple pieces of advice for improving bow performance, especially at the end. It is otherwise largely of academic interest, although personally I find it fascinating to understand how such a simple tool as a stick with some string on it can propel another stick with such speed and accuracy. If you don’t care about that then this might not be the post for you.

Bows

A bow is essentially a spring: a device that stores energy as it is deformed and then converts it into kinetic energy as it springs back, propelling the arrow as it does so.

The following discussions will deal mainly with attaining high arrow speeds with a smooth release, without damaging the bow. There are, of course, many other factors that may determine which bow and arrows you use and how you set them up. These include how sturdy they are, how forgiving and, frankly, just pure personal preference of how they feel. I am not addressing those features here. These posts are just about how they work, with particular reference to the storage and release of energy.

I have made some simplifications. In my last post I dealt with relativity and fine physical details. That was a bit of fun but has no real impact on how the bow works. In this post I shall simply deal with those factors that have a real effect on the bow. This means that I am missing out some physical effects that have a minor effect on the workings of the bow. I am just going to deal with the major points.

Storing Energy

Drawing a bow transfers energy into the bending limbs of the bow in the same way as stretching a spring or elastic band. Broadly speaking, the more energy it takes to draw the bow, the more energy is stored. Not all of the energy is in fact stored but for these purposes we will assume that it is. The total stored energy is therefore the total energy required to draw the bow back to full draw. This is not the same thing as the final draw weight.

Three States of the Bow

We shall consider three states of a bow: unbraced, braced and full draw. When unbraced (i.e. there is no string on it and no force is being applied to it) we shall assume that it has 0 stored energy.

It then takes a certain amount of energy to brace (string) the bow. Once the bow has been strung it will have a certain amount of stored energy. This will be the amount of energy required to pull the bow from rest to brace height. This energy is not available to the arrow because a shot bow returns to brace height, so the energy required to go from unbraced to braced is not released when you shoot. This energy is therefore lost for the purpose of shooting. For anybody who doesn’t know, the distance from the string to the belly of the bow at brace is called the brace height. A high brace height means that the string is a long way from the belly of the bow. A low brace height means that the string is close to the belly of the bow.

The final state of the bow is full draw. This is the furthest you pull it back and generally represents the point of maximum draw weight. The energy available to propel the arrow is the energy it takes to pull from brace to full draw.

It is worth noting here that a bow does not know when it is braced and when it is being drawn. Brace is simply a position along the draw when the bow is held by the string. Imagine bracing a bow at 9”. A person with a 28” draw length will now pull the string back 19” from brace to full draw. If the same person draws the same bow but it has been braced at 6” then they will pull back 22” to full draw, passing through the former brace height. This is an important point to remember later. A bow will have an optimum brace height. Changing your brace height will affect the energy storage and arrow speed as well as the feel of the bow.

For ease of calculation, I will in these posts generally use a bow that is braced at 8” and drawn to 28”. This is a fairly high brace height but it allows me to work with a drawing distance from brace to full draw of 20”, which is useful for calculations and examples.

Changing Draw Weight and Length

For a proper understanding of bow mechanics it is important to recognise the fact that there is no such thing as “a 40lb bow”. It is simply shorthand for “a bow that draws 40lb at a certain draw length”. (In the West this draw length will generally be 28”.)

This fact is important because the draw weight of a bow changes as you draw it. At 1” of draw (from brace) it might have a draw weight of only 2lb or so but at 28” the same bow might have a draw weight of 40lb. This affects the amount of energy required to draw it and therefore the amount of energy stored and available for propelling the arrow. Contrast this with lifting a 40lb weight from the floor. When you have lifted it 1” it weighs 40lb. When you have lifted it 28” it still weighs 40lb.

Now comes a crucial step: which requires more energy, lifting the 40lb weight 20” or drawing the bow 20” to a 40lb full draw weight? Obviously lifting the weight requires more energy, because you are applying 40lb of force for the whole distance rather than applying an increasing amount of force up to a maximum of 40lb. This demonstrates a vital fact: draw weight at full draw is not everything.

Imagine if the bow had a full draw weight of 45lb. You would still expend more energy lifting the 40lb weight 20”. The early weight requires more energy than the extra bit at the end. The same is true of two bows: a 45lb bow may or may not store more energy than a 40lb bow. It all depends on something called the force/draw curve, shortened to f/d curve.

F/d Curves

Take your bow and brace it. Then draw it 2” using a bowscale and measure the draw weight at that draw. Return the bow gently to brace and make a note of the draw weight at 2”. Repeat for 4”, 6” etc, right the way up to full draw (28” for these purposes).

Now draw a line graph. The x axis plots draw length and the y axis plots draw weight. Mark your points on the graph and draw a line or curve connecting the points.

I have drawn below the f/d curves of two hypothetical bows. The blue bow draws 1lb at 2”. The draw weight increases by 2lb per 2” of draw from there to 12” (draw weight 11lb), at which point the draw weight begins to increase more rapidly, going up by 4lb, then 6, 8 and finally 11lb for the last 2”. This gives a steep curve for the last few inches. That steep curve is something you can feel as you draw the bow. It suddenly gets much harder to pull the bow back. This is known as stacking.

The second bow draws 3lb at 2” and increases in draw weight by 3lb per 2” until 12” (draw weight 18lb). From there to 18” it increases by 4lb per 2” and the final 2” of draw increase draw weight by 5lb. The line is almost straight and this would feel like a very smooth draw with no significant stacking.

Notice that the stacking bow has a draw weight at full draw of 40lb, whereas the non-stacking bow only draws 35lb at the same draw length. If you looked at these bows you would see one marked “35lb” and one marked “40lb”. As we have seen, the 40lb would stack horribly and would therefore be unpleasant to draw.

The remarkable thing is that the 35lb bow also stores more energy. Stored energy can be calculated by calculating the area under the f/d curve. This requires some slightly tricky mathematics called calculus, since the line is unlikely to be perfectly straight. We do not need to do the calculations, however, to see that the area under the red line is greater than the area under the blue line: the blue line only overtakes the red one at the very last moment and this is not enough to outweigh the fact that red has been higher for the previous 18” or so. (Note that in this graph we are looking at draw length from brace rather than total draw.)

Now think back to our thought experiment about drawing a bow and lifting a weight. The f/d curve of lifting a 40lb weight would simply be a straight line at 40lb.

As a basic rule, for two bows of the same or nearly the same weight and with the same draw length and brace height you will store more energy with high early draw weight than with low early draw weight.

It is, of course, true to say that for two bows of the same design you will store more energy with a high draw weight, just as you will also store more energy with a longer draw length, all other factors being equal.

The obvious question is how do you spot (or design?) a bow with high early draw weight and therefore high energy storage? I am not going to answer in depth, since this would require most of a book in itself. I recommend the Traditional Bowyer’s Bible volumes 1 and 4 for those who want to know more. Suffice it to say for now that it is largely a function of the shape of the bow in each of its three positions and the thicknesses and widths of the limbs at various points. As a rule of thumb, higher energy storage comes with increased recurve and more with static than working recurve. Ultimately the best advice I can give is to try any bow out before you buy it.

Draw Length

All else being equal, a longer draw will store more energy than a shorter one. The reason for this is simple: you are applying force for longer. Going back to the weight analogy, it is harder to lift a 40lb weight 24” than to lift it 20”. A longer draw can be achieved either by pulling the bow back further or by using a lower brae height – if you pull to 28” from a 6” brace then the effective draw length is 2” longer than it would be from a brace height of 8”.

Brace Height

Before I go, I have one more thing to mention. If I had to name one thing that would help the most people improve their bow’s performance with the least effort it would be brace height.

In the first place let me explain, in case anybody does not know, how you change your brace height. Put simply, you twist your bowstring. If you put more twists into it you will shorten it. This means that the bow has to be bent further to brace with that string, which raises the brace height. If you remove some twists then you lengthen the string and therefore lower the brace height.

We have just said that brace height makes a difference to energy storage. We will see in a future post that it also makes a big difference to the conversion of that energy into arrow speed. I therefore have a plea: keep your brace height consistent. Wherever I go among horseback archers I see people unstring their bows and just leave the string lying next to the bow, or put it a bag etc. The chances of keeping the same number of twists in it if you do this are very small, which means that the next time you string your bow you will have a different brace height. Your bow will store a different amount of energy and will impart a different speed to the arrow, which will therefore not hit the same place.

Prevention is simple. Keep the same number of twists in the string. Either ensure that both ends of the string are looped over the bow or, if it is going to go in a bag or otherwise away from the bow, thread the bottom string loop through the top loop and then the top one through the bottom. Pull tight and the string cannot untwist. This takes about 3s and can save you all kinds of problems.

So much for energy storage. My next post will be on the second part of the arrow speed equation – transferring the stored energy into arrow speed. This is not so technical as the storage of energy. It consists of a number of fairly simple concepts, many of which can be used to improve the performance of a given bow, making the next post of more use to somebody who owns a bow and wants to make it shoot faster.

As always, comments are welcome. Happy shooting!

A Break With Tradition?

“Horseback archery is a traditional sport”. That fact is taken for granted by the majority of practitioners. It is recognised by UNESCO as being of cultural importance. We all know that horseback archery was the means by which countless waves of Steppe nomads swept over Asia and Europe, by which the Parthians and Persians fought the Romans and the great Arab conquests were achieved (at least in part). Fewer people worldwide realise that in Japan the tradition of yabusame has been practised continuously for some 800 years. I am grateful to Tanaka-san and to Tim McMillan for opening my eyes to this hidden (to me!) gem of mounted archery.

Recent discussions on Facebook have set me thinking again about the notion of a traditional sport. There are several competing philosophies in the world at the moment. The labels I have attached to them are my own and I make it clear at the outset that I do not believe any to be any better or more important than any other.

    Pure Martial Art

This is exemplified by the hundreds or thousands of practitioners of yabusame in Japan who do not compete abroad, do not compete in the Korean, Hungarian, qabaq, mogu or the other styles that we see in various countries. They simply do their own style, striving for perfection in it and treating the enterprise as an end in itself. I have not mentioned them much in what follows, simply because the pure martial artist is likely to agree, for these purposes, with the next category of person:

    Reenactment

This is the view that the ultimate question is “what did our ancestors do?”. There are few sights as impressive as a rider in full historical outfit galloping at full speed whilst loosing handmade wooden arrows from a horn and sinew bow drawing upwards of 100lbs.

    Competitive Sport

Whilst many people in this camp still enjoy and appreciate the fact that this is a traditional sport, for them the guiding principle is the sport. Fibreglass bows of a draw weight no higher than is necessary to send the arrow into the target; carbon or aluminium arrows for perfect consistency and generally functional clothing are preferred.

Of course these are extremes. Many people do not fall entirely within one category. Most fit somewhere in between but these are the three main views that horseback archery needs to cater for.

There are several areas where a balance needs to be drawn. One of the most obvious is equipment. I am thinking particularly of arrows, quivers and bows.

    Arrows

This can be simply stated: our ancestors did not have aluminium or carbon arrows. The reenactment view would therefore be that we should be using wood, bamboo or reed arrows. The sportsman would say that carbon and aluminium can be made straighter, lighter and more consistent than the traditional materials and so he would want to use them. In practice, most international competitions allow any arrow material, even if the rules technically state otherwise (in Sokcho in 2010 the rules technically stated that arrows must be bamboo. I therefore claim gold and silver on behalf of GB as I’m pretty sure we were the only ones using bamboo…)

    Quivers

At the World Championships in 2010 several Iranian competitors used “arm quivers”. These ingenious inventions consisted of clips attached to the armguard, into which the arrows were inserted. This made for vey fast reloading. Of course, such “quivers” are not historical. The martial artist and the reenactor would disapprove, even if they recognised the genius of the invention. The sportsman would applaud the innovation and adopt it if
they wanted to.

    Bows

This has been the topic of recent discussion on Facebook. Traditional horsebows do not have any form of arrow rest. They certainly do not have a cut out arrow shelf such as is found on more recent bows. The yumi, of course, has its unique length and asymmetry. It has no rest and no shelf. No horsebow, as far as I am aware, had a handle that was shaped to fit the hand in the manner of modern pistol grips. At present these innovations (pistol grips, shelves and rests) are banned under most competition rules. The reenactors would say that this is quite right. More and more sportsmen are saying that we should open our doors to a greater variety of bow designs.

Various arguments are put forward:

“Allowing other types of bow will encourage newcomers to the sport who are archers already, because they will not need to get a new bow”. This may be a good argument as far as it goes but to me it seems that it does not apply at the upper levels of the sport. By the time you are competing in international events you really ought to be able to buy a bow specifically for horseback archery.

“We don’t really know that our ancestors didn’t use these designs”. This seems to me to be a pretty poor argument, especially in relation to cut out shelves. We have lots of evidence from texts, art and archaeology, none of which suggests these design aspects. We know that handles tended to be relatively narrow. This makes it easier for the arrow to flex around the bow and means that a cut out would not be feasible (or as necessary). Admittedly a stuck on rest or a built up grip are possible. I suspect that the latter, at least, was probably used by some mounted archers. Nonetheless the burden seems to me to lie on those who say that such things are or may be historical to prove it.

“Our ancestors would have used them if they had the technology”. I have used this argument myself. I was rightly but delicately put right by a friend who pointed out that they would also have used firearms, which is no reason for us to turn our sport into mounted pistol shooting…

There is one more argument that is put forward. In my opinion it is the strongest but it is also possible the most controversial:

“We have already abandoned tradition”. It can be pointed out that we allow fibreglass bows, dacron or kevlar strings, plastic nocks on aluminium or carbon arrows with machined points, modern horse tack and personal clothing etc. We ride down a track that has been roped off and shoot at targets that are generally much closer than the enemy would have been for our ancestors. Surely, the argument goes, we have abandoned tradition already and allowing new bow designs would not take that abandonment significantly further.

It is difficult to think of a suitable answer to this point. To the pure reenactor the solution is to ban the other innovations. To the pure sportsman the solution may well be to allow all bow styles, albeit maybe creating different classes for different bow styles, as is done in regular archery. The problem only really arises for those like me who are sportsmen with a desire to preserve the tradition to some extent. Since that describes me rather well, let’s look at some of the counter arguments. (I should perhaps add at this stage that I hate the idea of different classes for different bow styles in mounted archery. At the moment men and women compete against each other using all different varieties of bow. Everybody is in the same class with no distinctions. Long may it remain so.)

It’s the look of the thing.
Carbon arrows do not look so very different from wooden arrows. You can’t tell, at a distance, whether a string is made of ancient or modern material. You could easily spot a modern bow though.
This argument does not stand up. You cannot spot, from any distance, whether somebody’s grip is a plain traditional one or a shaped pistol grip. You might be able to spot a cut out shelf but frankly if you can spot a small rest stuck on the side of a bow then you can probably tell whether the arrow is carbon or wood.
In addition, we allow bows to be made of modern materials that look modern. More than one of the Iranian team uses a bow with the word “Persian” printed in large letters down the upper limb and nobody objects to this. It looks good and advertises who they are. Clearly, then, looking ancient is not everything.

A variation on this argument is that whilst materials can vary, the design and form should be kept the same as the historical bows. While stronger than the previous version, this argument still suffers from a lack of consistency. We allow personal dress and horse tack that is not of traditional shape. We allow quivers that hold just the right number of arrows and hold them separate for easy drawing. How many ancient warriors rode to battle with only 6 arrows?
Besides which, unless you rely on the “it’s the look of the thing” approach with all its difficulties then it is difficult to see why the shape of the bow should be protected more than the materials.

They give an unfair advantage.
If everybody is allowed to use these modern designs then there is no unfairness. The advantage only arises if some people stick to using more traditionally shaped designs. That, however, is their decision. Until now I have resisted using carbon arrows out of a desire to remain more traditional. Undoubtedly my arrows were heavier than carbons and less well matched. This put me at a disadvantage but not an unfair one since I was free to go carbon. I know more than one other person, traditionalist at heart, who have abandoned traditional wooden arrows for the sake of carbon’s additional performance. I think we all felt a little sad but ultimately we want to compete.

    What Do I Think?

My opinion on this matter has changed recently and I daresay it will change further. I would love to see everybody using traditional equipment. That is unlikely to happen. That being the case I will modernise to keep up. My arrows are now carbon with plastic nocks and small silicone dots to help align the arrows in my hand. My bow has a fibreglass core and a synthetic string.

I would like to see bows remaining of traditional form, with no shelves or rests. This is largely an emotional response that I admit I cannot justify with strict logic. I have my doubts about the efficacy of rests and shelves on horseback but if somebody wants to try them then I believe they should be allowed. I just hope that nobody does.