Twelve settings, one arrow flight.

Brace height is the distance from the string to the throat of the grip on the braced bow. It sets how long the arrow stays on the string, and therefore how much of your shot the bow copies.

Tool

Bow square or brace gauge

Target

Maker’s value, or the table below

Adjusted by

Twists in the string

Knocks on to

Tiller, nocking point, sight marks

What it changes

A lower brace height means the string pushes the arrow for longer. You gain speed, and you also gain every fault in your release, because the arrow is still attached while the bow is still reacting to you. A higher brace height releases the arrow earlier: slower, quieter, softer in the hand, more forgiving. The manufacturer's range exists because outside it the string starts slapping the limbs at the bottom end and the limbs work outside their designed geometry at the top end.

Starting values

The recommended column is the starting value the Brace height test exercise gives you in CapTarget Archery; the published range beside it is compiled from club and coaching sources and shows the room you have in step 10. Both are a place to start, not a specification: makers publish their own bracket for their own limbs, up to a centimetre either side of the figures below. For a 72 inch bow, published sources often group 70 and 72 into one band, which puts the recommended value just above it. Your bow’s manual always wins.

How to set it

1. Brace the bow with a stringer, never by stepping through it.
2. Measure. If you are outside the range, unbrace the bow before you touch the string.
3. Brace too low, add twists. Brace too high, take twists out. Turn in the direction that closes the loops tighter on themselves, never the direction that opens them, because unwinding the string slackens it and wears it out.
4. Work in blocks of two or three twists, then re-brace and re-measure. What one twist is worth depends on your string (e.g. 2 twists ≈ 5 mm), so count twists rather than converting.
5. Stop at the recommended value for your bow length, or at whatever your manufacturer states. This is a preset; step 10 finds the real value.

Tiller is the difference between how hard the top limb and the bottom limb are working. You draw the string below its centre, so the two limbs need slightly different geometry to arrive back at brace together.

Tool

Bow square, Allen key

Split finger

+2 to +6 mm (FFTA)

Three under

0 to slightly negative

Linked to

Draw weight, nocking point

Why positive tiller

With a split finger hook, two fingers pull below the arrow and one above, so the hand pulls the string below its midpoint. The bottom limb therefore does more work. Making the bottom limb marginally stronger, which is what a positive tiller measurement describes, brings the two limb tips back into step. Archers who shoot three fingers under the arrow, or who string walk in barebow, load the string even lower and generally run tiller at zero or slightly negative.

Which figure to start from. Published brackets do not agree: the French federation gives 2 to 6 mm, Ely Archers and Stalker Stickbows 1/8 to 1/4 in, which is 3 to 6 mm, and Online Archery Academy 0 to +4 mm. This guide takes the federation figure, which overlaps both others. Anywhere inside that band is a legitimate preset; from step 8 the arrows settle the rest.

How to set it

1. Measure A and B on the braced bow.
2. Unbrace before turning limb bolts. Turning them under tension damages threads and pockets.
3. Tightening a limb bolt reduces that limb's tiller measurement and adds draw weight. Loosening does the reverse.
4. To change tiller without changing draw weight, turn both bolts by the same amount in opposite directions.
5. Keep every limb bolt engaged by at least six full turns of thread: beyond that, the limb can jump out of its pocket.
6. Re-measure brace height afterwards, because moving limb bolts moves it.

The string, both limbs and the riser should sit in one flat plane. If they do not, the bow twists as it fires and every horizontal setting you make afterwards is measured against a moving reference.

Tool

Limb alignment gauges, or tape marks

Target

String bisects both limbs and the riser centre

Adjusted by

Lateral limb screws in the ILF pockets

Do first

Before touching centre shot

How to correct it

1. Identify which limb is further out of line and adjust that one first.
2. Loosen the pocket locking hardware, then move the limb tip in the direction opposite to the string offset. If the string sits to the right of a limb's centre line, the tip needs to move left.
3. Make small changes, one limb at a time, and re-check after each one. Re-tighten the locking screws.
4. Check for limb twist separately: sight along each limb and see whether the tip is rotated. Do not try to cancel limb twist with the lateral screws, because that pulls the string off centre and trades one fault for a worse one. A badly twisted limb is a warranty issue, not a tuning problem.

Centre shot is where the arrow sits left to right relative to the bow plane. It is set with the plunger barrel, not the spring, and it decides how the shaft starts its bend around the riser.

Tool

Your eye, plunger barrel, rest arm

Right handed

Point just outside the string, to the left

Left handed

Mirror image, to the right

Prerequisite

Step 3 complete

Why not dead centre

Fingers cannot leave the string cleanly. The string rolls off the fingertips and pushes the nock sideways, so the shaft leaves bending. Starting the arrow slightly outside the bow plane gives that first bend somewhere to go, and lets the shaft flex past the riser rather than into it.

How to set it

1. Nock an arrow and seat it on the rest against the plunger tip.
2. Screw the plunger barrel in or out to move the shaft closer to or further from the riser. Lock the barrel when you are done.
3. Set the rest arm at the same time. The plunger tip should touch the middle of the shaft, not the top or the bottom edge, and the arrow should sit on the arm rather than balancing on its tip.
4. Check the arm length. It should support the shaft without projecting so far that fletchings can strike it.

The sight does not make you accurate. It records where your bow already shoots, so that the same aiming picture keeps producing the same result. Set it early so that the shooting tests that follow are not fought against a bow that misses the boss.

Tool

Allen keys, a big target, short distance

Golden rule

Move the aperture towards the group

First shots

5 to 10 m into a large boss

Output

A recorded mark for every distance

How to set it

1. Mount the sight and put the extension in the middle of its range.
2. Line the aperture up with the arrow, and set the elevation near the top of its travel.
3. Shoot three arrows at a big boss from 5 to 10 m. Never start at long distance.
4. Move the aperture towards the group in one go, then confirm with three more arrows.
5. Step back distance by distance, recording every mark.
6. Lock every screw, and check them again after a hundred arrows.

The nocking point fixes where the arrow sits vertically on the string. Get it wrong and the shaft leaves the bow pitching up and down, which shows up as a tall group and, confusingly, sometimes as fletching contact.

Tool

Bow square, serving thread or brass nocks

Split finger

5 to 12 mm above square, 10 mm to start

Three under

About 12 to 16 mm above square

Fine tuned by

Step 8, the featherless test

The numbers, and why sources disagree

Published figures run from 5 mm to about 13 mm, and they genuinely disagree: Easton starts a finger-released recurve at 1/2 in, 12.7 mm above square; Ely Archers give 6 to 12 mm; Improve Your Archery gives 5 to 15 mm above the rest and recommends 10 mm. Part of it is a measuring problem: measuring to the underside of the locator and measuring to the top of the nock differ by a whole nock height. The rest is a real difference of opinion.

Keep one rule so your own numbers stay comparable: measure from the square line to the underside of the top locator. Split finger, start between 5 and 12 mm; 10 mm is a safe first guess, and Easton’s 12.7 mm is the manufacturer’s own starting point, not an outlier. Three under, noticeably more. Wherever you start, the featherless test in step 8 moves it to its final place.

How to set it

1. Clip the bow square on the string and rest its arm on the arrow rest, kept truly perpendicular. Cheap squares grip the string badly, so check that it has not tilted.
2. Mark the square line, then set the underside of the top locator at your chosen offset (e.g. 10 mm).
3. Add a lower locator, or a second tied band, so the nock cannot slide down. Leave the arrow enough room that it is not pinched.
4. Check nock fit on the serving: the arrow should hang from the string on its own and drop off with a light tap near the nock. Too tight drags the nock, too loose lets it fall.
5. Prefer a tied nocking point over brass. It is lighter, it will not crush serving strands, and it can be moved by fractions of a millimetre with a fresh wrap.

The plunger is a spring that meets the shaft as it bends. It cannot fix a wrong spine, but within the right spine bracket it is the single most sensitive control you have over horizontal arrow behaviour.

Set now

Medium spring, mid travel

Contact

Middle of the shaft

Barrel

Locked at the centre shot from step 4

Fine tuned by

Steps 8 and 9

Preset values

• Spring: the medium spring for most target draw weights. Low draw weights with long arrows often need the soft spring; heavy setups need the stiff one.
• Tension screw: about mid travel, so you have room to go both ways during tuning.
• Contact point: the tip must press the middle of the shaft. Adjust rest arm height until it does.
• Rule of thumb: some experienced coaches aim for roughly 12 grams of resistance per pound of bow weight measured at the tip as it starts to move, which is about 480 g on a 40 lb bow, with the spring sitting near the middle of its adjustment at that point. Treat this as a sanity check for spring choice, not a manufacturer specification.

Also called the bare shaft test. Fletchings are a correction system: they hide bad launch behaviour. Take them off and the shaft flies exactly the way the bow launched it, which turns arrow flight into a readable instrument.

Kit

3 fletched, 2 to 3 unfletched, identical build

Distance

30 m for reference, out to 70 m

Read order

Vertical first, then horizontal

Goal

Bare shafts inside the fletched group

How to run it properly

1. Shoot into a soft boss at shoulder height so the shafts are not damaged and do not deflect on impact.
2. Put a target face at 30 m. Shoot a few fletched arrows, then finish the end with the bare shafts, all aimed the same way. Repeat for at least three ends before you conclude anything.
3. Throw out shots you know were bad. A tuning test made of average shots measures your form, not your bow.
4. Set the vertical before the horizontal: move the nocking point in steps of 1 to 2 mm until the bare shafts share the same height as the fletched group.

The four cases

The levers for each case are listed just below.

The levers, case by case

Bare shafts landing right of the group, right handed. The shaft is reacting weak, so it has to be made to behave stiffer. Coarsest lever first, finest last:

• Take poundage out of the bow, so less is asked of the shaft
• Have the shafts cut shorter, and let a coach decide by how much
• Drop point weight, trimming breakable points if that is what you shoot
• Build the next string with more strands, which adds mass to it
• Wind the plunger spring tighter, once everything above is settled

Bare shafts landing left of the group, right handed. The shaft is reacting stiff, so it has to be allowed to bend more. Same order, coarse to fine:

• Put poundage back into the bow
• Go up in point weight
• Build the next string with fewer strands
• Back the plunger spring off
• Fit longer nocks

Bare shafts too high or too low: raise the nocking point if they land high, lower it if they land low. Move it a few millimetres, run the test again, adjust again if needed, until every arrow sits on the same horizontal line.

The featherless test told you which direction to go. This step finds how far, and it is decided by group size rather than by arrow angle. The plunger takes up part of the shaft’s first bend. There is one spring setting where that cushioning best matches your arrow.

Method

Compare groups, not impressions

Step size

Quarter to half a turn

Distance

Between 30 and 70 m

Volume

2 to 3 ends of 6 to 12 per setting

Metric

Average distance from group centre

Protocol

1. Record your current setting: which spring, how many turns from fully seated (e.g. medium, 2 turns).
2. Choose three settings to compare: current, two turns softer, two turns stiffer.
3. Shoot at least two to three ends of six to twelve arrows at each setting, somewhere between 30 and 70 m, in the same session. Long distance is what separates the settings: at 18 m almost anything groups.
4. Mark every arrow on the target face as you go, and decide how many of your best arrows you want to keep for the analysis before you look at the numbers.
5. Keep the setting with the best grouping, measured as the smallest average distance from the group centre.
6. Then fine tune around that value with a smaller step, for example half turns.

Back to step 1, but this time with evidence. Somewhere inside the manufacturer's range there is a brace height where your particular limbs, string and arrows exchange energy most cleanly. It is audible, and it is measurable.

Range

Only within the maker's limits

Step

Sweep 2 to 3 twists, then refine to the mm

Signals

Group size, sound, hand feel

After

Recheck tiller, nock point, sight marks

Protocol

1. Start at the low end of the manufacturer range. Write down the exact figure (e.g. 21.5 cm).
2. Shoot a fixed block, for instance three ends of six, at a fixed distance, and record the dispersion.
3. Add two or three twists, re-brace, re-measure, and repeat. Work all the way to the top of the range. Aim for about 5 mm between measurements.
4. Listen as you go. The efficient brace heights are noticeably quieter, closer to a soft rush than a sharp crack. Feel too: less shock in the bow hand.
5. Once one height clearly wins, go back over it finely. E.g. if 22.5 cm wins, test 22.7 and 22.3 cm.
6. Set the winner, then recheck tiller and nocking point, and shoot a fresh sight mark. Brace height changes arrow speed, so your old marks are no longer exact.

A tuned bow still shoots the arrows you give it. Even inside one dozen, shafts differ in spine, straightness, weight, nock alignment and how squarely the point seats. Sorting finds the ones that do not belong.

Prerequisite

Bow already tuned

Volume

Many ends, one distance

Key discipline

Shoot blind to the number

Outcome

A competition set plus reserves

Protocol

1. Number every shaft near the nock end so you can identify it in the boss but not while shooting.
2. Shoot at a distance where your own group is clearly smaller than the target face, so an outlier is visible. Outdoor distances expose more than 18 m does.
3. Record each numbered impact for several ends. Discard ends where you know you shot badly, before looking at the numbers.
4. Look for arrows that sit off centre in a consistent direction, not for arrows that simply had one bad flight. One bad end proves nothing, the same side three ends running is suspicious, six ends or more makes it real.

What to do with a suspect arrow

• Rotate the nock by a third of a turn on a three fletch shaft, or a quarter turn on a four fletch, and retest. Carbon shafts are not perfectly uniform around their circumference, and nock orientation changes which side flexes first.
• Weigh it. A shaft several grains off its siblings will drop below them at long distance no matter how it flies.
• Check straightness by spinning it on a spinner or rolling it on a flat surface.
• If it still refuses to join the group, retire it to a practice set.

How many clicks move your arrows one scoring zone? Almost every archer underestimates it, corrects too little, and loses points to arithmetic rather than to shooting.

What it gives

Centimetres per click, and clicks per zone

Specific to

Each distance and each face size

Test shift

Large, for example 25 clicks

Volume

3 ends of 6 to 12 per position

What theory predicts, and why it is not your answer

The worked example below demonstrates the arithmetic, nothing more. Its numbers are not yours and you should not shoot on them: they rest on one sight model and one arbitrary sight radius, and changing either moves every figure in the table.

Take a published specification: a Shibuya Ultima moves the pin about 0.05 mm per click in elevation, twenty clicks to a full turn of roughly 1 mm, and about 0.04 mm per click in windage, twenty clicks to roughly 0.8 mm. Assume a sight radius of 0.85 m, shooting 70 m at a 122 cm face whose scoring zones are 6.1 cm wide:

Now compare it with a figure measured on a real bow. Coaching literature reports about 11 clicks to move one ring at 50 m on an 80 cm face, whose zones are 4 cm wide, so roughly 3.6 mm per click. The table above predicts 2.9 mm per click at 50 m: reproducing the measured figure takes a sight radius nearer 0.69 m than the 0.85 m assumed above. Neither is wrong: they are two different bows, and that is the point.

How to measure your own

1. Set your sight normally for the distance you want to calibrate. Shoot at least three ends of six to twelve arrows and establish the centre of that group.
2. Move the sight 25 clicks to the right. Shoot at least three more ends.
3. Move the sight 25 clicks up and shoot at least three more ends.
4. Eliminate arrows that sit far outside the grouping, since one wild shot distorts a group centre badly.
5. Divide each measured shift by 25 to get centimetres per click. Then divide the zone width of the face you are shooting by that figure to get clicks per zone.

Reading the result honestly

• It is not the same at every distance. The shift is proportional to distance, so a value measured at 18 m does not transfer to 50 m, and the zone width changes with the face as well.
• It is not perfectly repeatable. Shoot well, in good conditions, and exclude the arrows you know were badly shot. The more arrows you shoot, the more consistent the answer.
• Stick to the clicks the exercise indicates. The shift is deliberately large, because a few clicks move the group centre by less than the uncertainty on where that centre is, and you would be measuring noise. Do not adjust by any other amount, or the results will not be comparable.
• Windage and elevation usually differ on the same sight, as the specification above shows. Measure both.

These settings lean on each other: changing one obliges you to revisit the others. Keep this table where you keep your tools.

Fast diagnosis

Three habits that save more points than any setting

1. Write everything down. Brace height, tiller, plunger turns from seated, nocking point offset, sight marks per distance. If you cannot return to yesterday's setting, you cannot experiment safely.
2. Change one thing at a time. Two simultaneous changes produce a result you cannot attribute to either.
3. Measure before every session. Brace height takes ten seconds and explains some of those "mysterious" bad days.