# weight on string theory

774 8
just a crazy thought

but if a peep and a kisser button rob you of speed and thus the possibilty for more KE
then why not add the same amount of weight as speed nocks above the bottom cam?

lets discuss
1 - 9 of 9 Posts

#### 60X

· World & National Champion
Joined
·
34,042 Posts
It all has to do with proper weight on the string at the proper locations. When this is optimal the string loses vibration thus putting the energy into the arrow for more speed.

#### gjarcher

· Registered
Joined
·
1,094 Posts
It all has to do with proper weight on the string at the proper locations. When this is optimal the string loses vibration thus putting the energy into the arrow for more speed.
This ^

Using speed nocks, I've gained almost 3 fps on some bows, lost a couple of fps on others.

#### trucker3573

· Registered
Joined
·
8,772 Posts
Don't understand the question posed....even a little?? Speed nocks create extra acceleration by adding a "whip" effect to the string don't they?

Sent from my SM-G930V using Tapatalk

#### Ohbowhunter815

· Go Bucks
Joined
·
2,292 Posts
You would be increasing the overall mass on the string decreasing the energy available to the arrow. Add speed nocks to a bare string in the proper position you can gain a small amount of speed. Get too much weight with added speed nocks and your speed will decrease.

#### nestly

· Registered
Joined
·
8,091 Posts
Don't understand the question posed....even a little?? Speed nocks create extra acceleration by adding a "whip" effect to the string don't they?
The opposite (at least in some cases) Hoyt has a video that shows how speed nocks help prevent "whipping" by keep the string down in the cam groove.

As for adding weight to the center of the string, any energy that might be gained is then lost when the arrow and string detach, so in all cases, it would be better to just add that weight to the arrow instead of the string so the extra energy remains with the arrow.

#### gjarcher

· Registered
Joined
·
1,094 Posts
...Speed nocks create extra acceleration by adding a "whip" effect to the string don't they?
A ''Whip effect" requires one end to be unattached, which is not the case for a bowstring.

A bowstring actually goes slack due to overtravel before the arrow detaches. During the fraction of a second of this slack period, the string is free to oscillate. The string can oscillate in synchronization with the limb oscillations or out of synchronization. If the string is not in synchronization with the limb oscillation, the opposing forces depletes energy that could have gone into the arrow. The bowstring's overtravel and subsequent oscillation can be seen in this slo-mo video for Blazer Vane performance:

By positioning weights on the string, its natural nodes and frequency of oscillation can be changed. The proper weight in the proper location can improved the string's synchronization with the limb oscillation, conserving energy and quieting the bow, assuming the the string requires added synchronization in the first place. Adding weight to a string that is already adequately synchronized with the bow's limbs upsets the the system and can result in arrow speed loss instead of gain. Adding a string stop complicates any theoretical calculation, so the only practical way to determine the affect of adding weight on a bowstring is to shoot through a chronograph. Some bows may gain a few fps, some may show no change, and some may lose a few fps depending on the original engineering.

If one has too much time on their hands, which is usually my case, experimenting with speed nock weights and positions, monkey tails on/off, various brands of string silencers, etc. can be interesting ... but don't expect more than ±2 fps for your efforts. The greatest affect of speed nocks will be had for very lightweight arrows (5 gr/lb) and less affect for heavy arrows. In the 15 years I've had a chronograph for experimenting with speed nocks/string silencers/eliminator buttons/etc on Hoyt/Browning/PSE/Mathews bows, I have never realized the 6~12 fps often claimed.

... hope this helps.

#### xman59

· Registered
Joined
·
13,757 Posts
just a crazy thought

but if a peep and a kisser button rob you of speed and thus the possibilty for more KE
then why not add the same amount of weight as speed nocks above the bottom cam?

lets discuss
forget the ke difference because it is not enough difference to make any,,, nocks placed in the right spots can add a few fps, in the wrong spot they can take it away, if you do not have a chronograph you will not be able to tell the difference any way... the most i have ever seen was 8fps, and that was only once, most of the time it is more like 2-5fps, gain, i have seen as much as a 10fps loss....

#### Luke Cool

· Registered
Joined
·
1,034 Posts
Speed nocks are strategically placed to where the motion of each part of the string is engineered to concentrate the energy transfer into the string's center position.
The speed nock's weight pulls on each end of the string during the arrow's acceleration. This keeps tension on those parts of the string, and limits vibration and noise.
It has somewhat of a whip effect. The drag on part of the string during travel causes an extra push at the end for the same reason a Bull Whip is tapered.

Someone got it backwards. A ''Whip effect" requires at least one end to be attached, but you can use multiple attachments.
A Bull Whip concentrates the energy from a large movement into a very small area.
In the case of a bow; It concentrates the energy from two large movements into one very small area.
Two Bull Whips with the ends tied together, if moved in unison, will still crack.

1 - 9 of 9 Posts