String Stretch & Arrow Tuning?

Stringwacker · February 02, 2022, 07:56:45 AM

Reading through the silencer thread got me to thinking about something I don't ever recall being discussed. While silencer weight is understood to make some rather significant changes in a bare shaft arrow tune (say for example cat whiskers vs yarn etc) has anyone ever noticed that as the string stretches from new to its eventual worn replacement... that it progressively shoots the arrow 'harder' over time?

Some disclosure is in order. I'm an 'arrow' guy. Some folks really get into bows looking for the holy grail. I missed that addiction somehow and over the last 50 years have focused on arrows. I have hundreds of all different types, weight systems, and broadheads for ever possible scenario. In short, I notice what most people wouldn't even care about. It's a hobby that I enjoy.... just because I enjoy it.

What I find is even a string like Dynaflight97 stretches. It's pretty obvious in the beginning but it mostly finds a landing spot pretty quickly that has little stretch. But.... as time goes on you are adding a twist or two every couple of months to keep the brace height the same; especially in the hot summer. The string gets skinnier as the wax decreases and the string gets tighter as you twist it....at least that is how I'm seeing it.

The end result....I've always noticed a very significant bareshaft tune when replacing a one or two year string with an new one (I'm in that cycle now) and will need to shoot a slightly heavier head with the new string to get a good bareshaft.

I'm guessing more than a few will be saying as long as the arrow still shoots with feathers why does it matter? I guess it doesn't but I definitely see a bit a squirreliness with a heavier broadhead head at some point as the string stretches if you start with a perfect tune. (Maybe like shooting a 125 Eskimo to a 115 Bear Razorhead) so we aren't talking massive changes.

Anyone ever notice this?

Orion · February 02, 2022, 09:30:26 AM

I've been at this now for more than 60 years, and I suspect I'm not good enough to get a perfect tune. For example, changing the location or material of my string silencers doesn't change my tune enough for me to recognize it. Perhaps that's why I've also never noticed any difference in arrow flight over the course of my bow string's life. Actually, I change them about every year, long before they wear out, but still haven't noticed any difference.

Stringwacker · February 02, 2022, 10:11:06 AM

Obviously I'm a bit of an oddity....bordering on eccentric some people would say. Drives me nuts to shoot an arrow that isn't tuned to perfection.

Probably another thing that I have noticed is that if all things are equal, a vented head will shoot the arrow stiffer (meaning like a slightly less point weight) vs a vented head. I guess all of this is like debating how many angels can dance on the head of a pin; its too trivial to matter.

SS Snuffer · February 02, 2022, 12:44:54 PM

I must be the same as you Stringwacker, I am trying to see how cock feather orientation effects tune, but most say "that's why we shoot feathers and it don't matter".

Stringwacker · February 02, 2022, 02:52:15 PM

Just because I wanted to know....

I took my old string with a Big Jim yarn mini silencer and got a string weight of 122 grains. I took a new string and another silencer made by Big Jim of the same type and it weighed 130 grains...8 grains difference. I assume the difference is the wax that has been lost shooting the old string. While that's enough that I might barely see it on a single bareshaft arrow tune; not likely to be enough to get the significant tune difference in itself that I'm seeing.

Understanding that non-stretch strings shoot harder; it might just be the old string had all the available stretch shot out of it compared to the newer string.

Orion · February 02, 2022, 03:58:03 PM

SS: CDock feather in provides a little more clearance and will straighten out some arrow flight problems. However, if the nock point is set right and the arrow well tuned to the bow, it isn't necessary to turn cock feather in. A lot of folks do, though, because of the better flight one gets if everything isn't in tune.

I switched to 4-fletch several years ago, but when I shot 3-fletch, after I had my arrows flying like I wanted them, I never paid attention to how I nocked them so I might be shooting cock feather in on one arrow, and cock feather out on the next. They all shot the same.

jhg · February 02, 2022, 04:11:43 PM

The strings I choose, once settled in, do not change. I can string my bow and it will need no adjustment after I set BH in a month hunting all weathers.
I check it of course but rarely need to adjust it.

Stringwacker · February 02, 2022, 04:49:20 PM

jhg, your likely on to something....

I've used the same dynaflight97 strings from the same source for almost 30 years. They definitely stretch as I have to adjust slightly the brace height every month or so ...as i said earlier especially the summer when its hot and I'm shooting daily. The strings get skinnier over time and I have to re-tie the nocking nail knots.(I assume due to it) Over the life of the string; I'm likely twisting 5 to 10 turns after that first month.

Either the string I use has some stretch in it or is heavily waxed and is just bleeding out.
Thanks