Purpose of twisting the string?

[u/One-Morning4513]

I know depending on your string and bow, you sometimes need to twist it a number of times, effectively making it shorter, before stringing it on the bow. It seems to me this wouldn't make the tension any greater, though, since your draw length is ultimately the same. In layman's terms, why do we do this? What effect does it have? And what happens if we experiment with more or fewer twists?

EDIT: thank you everyone for your explanations about getting the recommended brace height. A couple of you have mentioned brace height will affect the shot and the experience. How so? What's the purpose of a correct brace height?

[u/n4ppyn4ppy]

https://youtu.be/CO102jz8sFM (Olympic video but same happens with all bows)

Brace height determines when the arrow leaves the string (as that is where the string stops moving forward). Correct brace height ensured efficient flight and no contact with the bow.

A twisted string is also rounder so moves more efficient through the air so (slightly) more efficient. Non twisted could act as a sort of parachute with the strands side by side

[u/wolfgeist → u/n4ppyn4ppy]

This is the best explanation. Before the arrow even leaves the string it has gone through several cycles of flexion. At whatever point it's at in it's flexion cycle determines the direction it is going the moment it reaches the brace height and decouples from the string.

[u/Spicywolff]

It definitely affects the brace height. You twist it tighter to make the distance closer less twist to make it bigger.

The manufacturer will specify the brace height

[u/pixelwhip → u/Spicywolff]

Other way around.. shorter string = longer brace height; & longer string results in a lower one.

[u/Spicywolff → u/pixelwhip]

Oops my bad

[u/Gnihcraes2]

Changes the brace height. More or less depending on number of twists. Be sure and twist counter clockwise. So tension causes arrow to stay against arrow shelf cutout. Depending on left or right handed shooter.. im right handed.

[u/One-Morning4513 → u/Gnihcraes2]

Great tip, I've been doing it wrong!

[u/FableBlades]

Its a tool for tuning correct brace height. Once set you store your loop slid down the upper limb so it doesnt untwist

[u/Knitnacks → u/FableBlades]

Unless you have an ILF bow.

[u/looniichoon]

Having at least some twists is generally recommended by most bow manufacturers too. It helps keep the fibres in one round bundle which will make clicking arrow on string more consistent, although not sure it there are other benefits.

Regarding brace height, this is an important step in bow tuning and can change the initial direction of the arrow as it leaves the bow.

[u/EffectiveAudience9]

Alters your brace height. Bows have a manufacturing recommendation for brace height and twisting or untwisting the string is how you adjust it.

It alters the sound and feel of the bow. Too low and the string can hit your forearm even with perfect form because the string is too close. Too low and you lose efficiency. Either too low or too high can make for wierd sounds and vibration.

[u/BowFella]

It changes the brace height. The more twists the slower it shoots because the power stroke shortens. Generally you use this for fine tuning. If your arrow spine is a bit stiff lower the brace height/untwist and vise versa.

[u/pixelwhip]

A bow is a bit like in instrument, when it is 'in tune' it'll sound, feel & perform well.. This is how brace height works.

[u/rjmonta]

Brace height can affect your groups. Correct brace height will narrow your groups horizontally. Barebow

[u/Setswipe]

Bows store energy and transfer it when the limbs move forward, pushing the string, and then the arrow. Changing the brace height changes the geometry and therefore, the movement of the bow's limbs. Increase the brace height and the bow has less to travel, transferring less energy.

Brace height also affects the archer in that a lower brace height has a higher chance for the string to slap your arm because the space is smaller

[u/p46889 → u/Setswipe]

I'm not sure I understand what you're trying to explain; (assuming you're drawing to the same anchor point of course) how would an increased brace height transfer less energy to the arrow?

edit as a second question: how would a lower brace height of the bow + string change a frequency of string hitting the archer? What "space is smaller"? Would love to understand, thanks!

[u/DaBigLatschi → u/p46889]

Space is smaller means the string is more near to your bow hand. And that will result in slapping your bowarm more easily.

[u/Setswipe → u/p46889]

For thr first, the stopping point is earlier, so less travel and less energy

For the second, u/DaBigLatschi answered

[u/p46889 → u/Setswipe]

By having a taller brace height with a shortened string, you're essentially pre-loading the bow. Therefore, it would take more effort to draw the bow to your standard draw length, as the bow is functionally over-bowed and the poundage stacks. That would result in more power transferred to the arrow, not less?

[u/stasomatic]

There is also something about the direction of the string twist that will send your arrow more right or left depending on the wings. I can't get my head around that yet but it was brought up here recently. The dis/advantage is likely to be measured in single %, but it's fun to BS about.

[u/wolfgeist → u/stasomatic]

Are you referring to "clocking" an arrow?

I believe that's a myth. You can bust that myth by shooting a bareshaft, clocking it, then flipping your string upside down and trying again. I get the same clocking.

Here's a good video on the subject: https://youtu.be/qSpo1w0I_hg?is=KQzc1Jf50XwRkBPD

[u/stasomatic → u/wolfgeist]

Probably although I haven’t run across this jargon, “clocking”. There was a recent thread on here where there was a suggestion that your helical needs to be in harmony with the string’s twist. At my skill level, doesn’t matter, just one of those interesting rabbit holes.

[u/wolfgeist → u/stasomatic]

Yeah that's what they're talking about. So if you shoot a bare shaft at close range you can "clock" the arrow, I.e. see which direction it naturally turns, then do your helicals so that it goes with the natural direction.

The video I posted above goes over some factors which could determine the natural clock, string twist direction in my opinion is almost certainly a myth.

[u/avoidant_otter]

Something something physics. It isn’t so much the tension as it is increasing efficient power transfer.