What is brush nocks?

[dolgima]

http://www.primitivearcher.com/smf/index.php/topic,45523.0/nowap.html

I saw this post but I couldn't understand what is brush nocks. English is not my mother tongue so I searched dictionary about "brush"  (an ​object with ​short ​pieces of ​stiff ​hair, ​plastic, or ​wire ​attached to a ​base or ​handle, used for ​cleaning, ​arranging ​your ​hair, or ​painting) but I think this is not the meaning of brush in archery. Can someone explain "brush" and brush nock easy way?

And what is the purpose of using brush nock? I read some comment but i coudn't understand. brush nock is something like bridge in horsebow?



(Yes, they do serve a purpose.  They're desinged to keep brush from snagging between the string and belly of the limb on recurve bows.  This is not only annoying, but can really wreck/twist/break a recurve if you're not careful.  As far as hand shock goes, it's a bit counterintuitive.  If you have working recurves or a very short recurved/flipped tip, then yes, this style of nock tends to add a bit of shock.  However, if you've got a pronounced static recurve, then no, I've found I get no hand shock (assuming the limbs are tillered/timed properly!).  Brush nocks tend to exaggerate any tiller/timing inaccuracies.

The above reasoning works on the much the same principle as a horsebow.  Logic would suggest that those long levers (siyahs) would jar your teeth.  However, for a number of reasons, horsebows are amonst the smoothest drawing and shooting bows.)





(Grumley’s Deerslayer is the father of the Kodiak. These were made in a variety of material configurations but all had the large brush nocks, which helped eliminate brush getting caught between the string and limb of the bow)

[DavidV]

Brush means grass and weeds. The brush nocks keep grass from getting caught between the tips and the string when you're in the field. The other purpose is lowering vibration during the shot like the bridges on a horsebow.

[PatM]

Brush  is just an alternative name for bush, shrubbery etc. Look at a picture and you can see how the scooped out section allows twigs to just slide through the groove without getting caught.

[Pat B]

Brush is also twigs and branches. Like David said, brush nocks are made so your bow(primarily recurves or with reflexed tips) doesn't get hung up on brush as you walk afield.

[dolgima]

Brush  is just an alternative name for bush, shrubbery etc. Look at a picture and you can see how the scooped out section allows twigs to just slide through the groove without getting caught.

thank you for reply. so brush nock is just for hunting. There is no energy efficient advantage or effect on brush nock?  only add weight on tip and decrease efficiency?

I read some comment that bursh nock act like lever so early d/f curve is steep(3-4 pound per inch) and  end of draw is gradual(1-2pound per inch)? is it true?  I think this is effect of recurve(siyah) not brush nock..

[PatM]

 Yes, generally a hunting bow feature although if you rove and stump shoot in that type of terrain  then it's handy then as well.
   The tip weight undoubtedly decreases efficiency but nowhere near what you might expect. The  thoughts of how abruptly stopping the string on bridges may help is another  scenario that's hard to test.

[Springbuck]

[/quote] I read some comment that bursh nock act like lever so early d/f curve is steep(3-4 pound per inch) and  end of draw is gradual(1-2pound per inch)? is it true?  I think this is effect of recurve(siyah) not brush nock..
[/quote]

 Yes, a recurve would do this better, and I have not made brush-nock bows before, but I think I can explain this.   I sometimes make recurved or reflex bows with a small "string bridge" on the upper limb. It is like at the "knee" of a bow with a siyah, usually there is a small pad or built-up spot of leather or something else, to help center and pad the string.  So, for example, let us say I built a recurve bow of wood.   I don't want to make a groove down the recurve for the string to rest in.  Instead, I take a small bamboo piece, 3.5 cm long X 1.5 cm diameter, and tie this to the limb, perhaps 12 cm from the tip, on the belly of the recurve.  I cut a small groove in that for the string to rest. So, when I string the bow, the string now rests in that groove and the bamboo is crosswise under the string.

The bamboo holds the string away from the bow slightly, and makes the string very tight while braced.  When you pull back the bowstring, this little bridge makes the bow act like the recurve is even more than it is, until the string lifts off the bridge as the limb bends back.

A brush-nock on a static recurve creates the same effect.