One Cam Bow Questions
 

I bought a Parker Hunter Mag 2 this year. Granted the bow was a 2001 model that had been used as a demo bow in a pro shop last year. The bow has been shooting fine up until a couple of weeks ago. I noticed then that I was getting wear on the bottom of my vanes. I use a Whisker Bisquit with the cock vane up. After looking at the set up, I noticed that my nock point (I shoot a loop) was higher than it should be. The loop had not moved up on the string (at least I don't think it has) it was really tight, but I'm wondering if my string has stretched enough to cause nock point to move.

So, my questions are:
1. When the string on a one cam bow stretches, which direction will the nock point move?
2. On the new zebra strings (like Parker and other manufacturers use) how long (how many shots) does it take before a string shows signs of stretching?

Thanks in advance for any thoughts you might have!

RE: One Cam Bow Questions
 

I'm no expert by any means but i think a string will stretch until you get a few hundred shots on it.about your nocking point,can you just move your loop down?check to make sure your loop is tight and isn't gonna slide up on ya.i'd bet your string did stretch.jmo.

RE: One Cam Bow Questions
 

1. Your nock point will move up when the string stretches as most of the string is above the nock point.

2. I believe Parker is using, or was using, Brownell D75 material but, regardless, as js stated, it usually takes a couple hundred shots for the new string materials to settle in completely.

RE: One Cam Bow Questions
 

PABowhntr,

So, you think after a few hundred shots, the string will stabilize on the stretching? I've probably shot this bow 1,000 +/- times and there was a significant change inthe loop position. The loop was tight so all the movement had to come from string stretch. I had really begun to see a lot of arrow torgue going down range. I plan to shoot during lunch today to see the effects of moving the loop back down. Of course that means reseting the pins again. No biggie...

RE: One Cam Bow Questions
 

<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>
1. Your nock point will move up when the string stretches as most of the string is above the nock point.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>

PA, it would seem to me that would cause the nock point to move down. Maybe I'm visualizing it wrong, but that's how I would expect it to move.

RE: One Cam Bow Questions
 

Danny,

If you are still getting significant movement on your string loop after 1000+ shots then it would lead me to believe that you are either shooting a bow with the older fastflight string material installed (which shouldn't be the case provided the bow you mentioned has the original string/cable on it) or the string loop is moving. Now, you did state that you didn't believe it was the string loop but I would ask you how you know that it isn't? Did you mark the string both above and below the loop knots to use as a baseline to judge movement? If you haven't then try it and see what happens.

Something else to consider is that maybe your center serving is moving and not the string or the string loop itself.

Straightarrow,

I was trying to visualize it for awhile too and I kept coming back to the image of a rubber band. Imagine stretching a rubber band over a door knob. As the rb is stretched the material &quot;moves toward&quot; the point where the most pressure is being applied. In the case of the rubber band that would be the door knob. In the case of the bowstring it would be the idler wheel...unless I am missing something here.

RE: One Cam Bow Questions
 

PA,

The reason I say the loop isn't moving is 2 fold. 1. The pro shop just replaced less than 2 months ago. 2. When he installed the loop, he did something I had never seen before. He ties some sort of string on either side of a nocked arrow, then ties on the loop, then on the outside of the loop, he ties another set of knots. I tried to move it before..... that sucker is in there TIGHT! I'm hoping it was just string stretch.

RE: One Cam Bow Questions
 

<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>I was trying to visualize it for awhile too and I kept coming back to the image of a rubber band. Imagine stretching a rubber band over a door knob. As the rb is stretched the material &quot;moves toward&quot; the point where the most pressure is being applied. In the case of the rubber band that would be the door knob. In the case of the bowstring it would be the idler wheel...unless I am missing something here.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>

I'm still trying to see that, but my mind isn't cooperating. :)

I vizualize it this way. Take a 100&quot; string and mark a spot 30&quot; from one end. Stretch the string one inch. This inch of stretch should be evenly distributed along the full length of the string. This would mean 7/10 of the inch is now added to the point above the nock and 3/10 added to the point below the nock. Now you have an even greater disproportionate amount of string above the nock. This means the nock is 4/10 of an inch closer to the short end, then it was before, or below the original nocking point. Does that make any sense?

RE: One Cam Bow Questions
 

Yes, it does make sense to me but then again so does my elaboration...<img src=icon_smile_wink.gif border=0 align=middle>. I am confused now too...<img src=icon_smile_big.gif border=0 align=middle>

RE: One Cam Bow Questions
 

Ain't it wonderful how progress has simplified our lives? <img src=icon_smile_wink.gif border=0 align=middle>

You know, I get plenty of string creep on dual cam bows. Brace height and axle to axle change, big time. Nock point? Hardly ever. The only way I know something is amiss is when I notice the bow making a little extra noise that it wasn't making before. Accuracy and shot placement never degrade a bit.

RE: One Cam Bow Questions
 

I have been watching this for a while on my bow(Hoyt Havoc,redline cam)and my buds Mathews FX,and noticed when the strings on these bows have stretched the nock has moved up.Another reason I make my own now,out of BCY452.:)

RE: One Cam Bow Questions
 

I am surprised to hear that Drstalker. Hoyt has been using Brownell D75 material on their bows since the first year the Havoc was introduced and I have found it to be one of the better, low creep, string materials. But then again I guess there are exceptions to every situation...<img src=icon_smile_wink.gif border=0 align=middle>

RE: One Cam Bow Questions
 

You are right about that ,but last year or year before<img src=icon_smile_blush.gif border=0 align=middle> I forget.I changed my string out with a Zebra,for a hog hunt in Florida(just because)and noticed the Zebra string stretching.I took an intererest in making my own and started using the 452.What is the qualities of the D75?I know the 452 is a low strech string and a bit slower than fastflight,and sume of the others.What is your take on this?Bill D&gt;

RE: One Cam Bow Questions
 

http://www.brownellco.com/pages/archeryMAIN.html

This should help you out some...<img src=icon_smile_wink.gif border=0 align=middle>

RE: One Cam Bow Questions
 

Assuming you get some string stretch, and I'm sure most will, what is the &quot;best&quot; way to get back to the original position for single cams?
Also, how much stretch would be considered &quot;tolerable&quot;?
I've always shot dual cams, and like arthur said, even with stretch, accuracy has never suffered.

RE: One Cam Bow Questions
 

I'd like to applaud ArthurP and Frank in his later post for using the term &quot;creep&quot; which is the correct terminology for the permanant elongation of a string. &quot;Stretch&quot; is a temporary elongation, as in a rubber band.

But I nitpick. <img src=icon_smile_big.gif border=0 align=middle>

<font color=blue>Good Luck and Good Shooting</font id=blue>

<font color=red>Rob</font id=red>

RE: One Cam Bow Questions
 

I'm not sure as to the direction that the nock would move after creep, but I do know that the rubber band/door knob analogy is bogus. (Sorry, PA!) First off there isn't any moving of material or more pressure at the door knob. (Principal of equal and opposite forces: knob and fingers are applying equal force at points that they contact the rubber band.)

Ignoring higher stress points (where the string goes over a sharp contour on the cam, etc.), the entire string is under the same tension. When creep happens to the material, its properties would dictate that (for example) when 1.00 inches of this string is loaded at 60 lbs, it will eventually deform to a length of 1.02 inches. In this example, if the string was 100&quot; long and 70&quot; of string was above the nock point, after creep the part above the nock would be 71.40 inches and the 30 below would then be 30.6&quot;. A net difference of the nock point moving DOWN 0.8&quot; (1.4-0.6).


Danny,

As for other ideas as to why your nock point moved, have you made any adjustments to the limb bolts? Comparing tiller may point to one cause. Remember, if one bolt is turned ANY more or less than the other, the nock point will move!