Torges' bow standards

[Flashman]

As I was stump shooting through the woods this afternoon after 100 arrows loosed from my vine maple bow I recalled Dean Torges' belief that one measure of a good self bow is that it can remain strung the entire day without loosing significant poundage.  I was wondering if my bow was loosing poundage as the number of shots continued and the day went on.  I concluded at the end I think it lost a little.  Do you think Torges' all day strung standard without significant loss of poundage including constanting shooting of the bow?

[NTD]

No I don't think that is what was meant.  I think he meant that you"re hunting for 8 hours, finally get your shot and your bow performs like it was just strung.  JMO

[Thwackaddict]

Nate  I agree 100%!I would say constant shooting all day would affect even the best built bow in some slight way.how much did you lose?

[Parnell]

I would lean the way of NTD's thinking.  Guess it's an arguement for building a bit heavier than needed...

[Badger]

One time I left a bow strung for a year, at the end of the year the bows string was loose and the brace height was permanent set. I seldom keep a bow braced for over 4 hours or so but I know their is a big difference in how some bows handle long periods of shooting and how others handle it. The dryer the wood is the less effect it will have. One of these days I am going to store one braced slightly backward and see how well it holds the stored reflex. I know some guys here have done that. Steve

[adb]

Hmmm... interesting concept, Steve. Do you think the reverse bracing idea would cause increased limb stress, once the bow was re braced properly? I think it might, leading to premature failure. Also, I'm wondering how long the reflex would last, and would it simply be "pulled out" as the bow remembers it's initial set? Interesting stuff.

I know the Torges standards were tested in an alternate trad archery forum (which no longer exists, unfortunately). There was a call to bowyers to submit their work for extensive testing, and this idea of prolonged brace was one of the criteria. Very informative stuff... I still refer to it occasionally.

[JW_Halverson]

I used to back bend my bow after unstringing to help it take up what string follow naturally occured after shooting.  Then I realized I was not doing anything that the bow would not do for itself if allowed to hang and rest. 

I think leaving a bow strung too long allows tiny little cellular fractures to add up until the bow has taken a set.  Set is permanant and irreversable...damage done.  I think backbracing will not add strength to the bow, it will just cause set in the reverse bend and compromise the fibers on the back of the bow.  Maybe some of the engineering types could support my theory or pick it apart.  I'll be watching with interest.

[Pat B]

A bow has to be able to handle relatively long brace times just to be able to hunt and target shoot effectively. I think that bracing and unbracing has more adverse effects on a bow than 4 or 5 hours of being strung. Stress is limited when a bow is at brace. Full draw, where the max stress occurs generally only last a second or two. I guess hunting would be less stressful(to the bow) than target shooting because of the difference in numbers of full draw pulls during a specific period of time. But, no matter what you use your bow for you want it to preform as well at the end of the session as it did in the beginning.

[Flashman]

I think someone asked how much weight or cast was lost.  I don't know.  The pull weight didn't seem any different to me at the end of my day but I did notice a slight wobbly arrow flight from one arrow (the highest spined one--about 5 pounds greater than the others) that shot fine earlier in the day.  I attributed it to a loss in poundage (probably not the right term); I didn't have scale with me.  This made me try figure out why and then remembered Torges' challenge, hence this post.

Thanks for all of the replies.

[Eric Krewson]

I have noticed a slightly reduced performance out of my selfbows after abut 4 hrs of steady shooting. Unstring the bow for a little bit and everything comes back. I don't see this drop in my bamboo backed bows.

[Badger]

 ADB, I built a bow for that challenge but didn't get selected. I still have the bow and love it. I left it braced for several days with no change, pulled to full draw and left it there for over an hour with no change. I wanted it stable by the time torges tested it. Nothing really changed and no loss in draw weight once I cameoff the tillering tree which gave it a pretty thourough workout anyway. Steve

[El Destructo]

I have a Flax backed Red Oak Board Bow that has been strung for three years now...This Bow was built to Hunt ...but it made that Notorious Ticking Sound...so I fixed it...Strung it...added Feathers...Leather Lace...and a dream Catcher...and made a Medicine Bow from It...and this Bow still is in full tension at Brace....I think when I get time...I will take it down...take off the Dream Catcher...crossed Arrows and Feathers and see just what it draws like...and the Poundage....and report back to you guys...

[Lombard]

Mike, I for one would be interested in the results of that experiment. I use linen often enough on marginal bow wood, but have never tried the combed flax.

[El Destructo]

This was combed...and laid just like Sinew would be...I'll have to wait till the Wife goes to Town or work...before I tear this apart!!

[JackCrafty]

I usually notice more loss of poundage after the first full draw than after 4 hours of shooting.  I don't hear many guys talking about this initial loss, but I experience it in many of my bows, especially the hickory ones.  Perhaps the bellies should be flatter and wider on these bows, I dunno.

Anyway, we need to determine what a "significant loss of poundage" is.  Maybe more than 1% would be significant?  There is also an engineering principle called "fatigue failure" that states that all materials will eventually fail when subjected to continual, repeated stress.  This principle is used to predict the life span of bridges, for example.  For every car and truck that passes over, a slight amount of stress is applied to the bridge.  Eventually the bridge will fail if traffic keeps passing over it.  The failure might begin with a small crack, and then expand from there.  Or the surface may wear out, etc.

Fatigue failure applies to bows as well.  Every shot brings the bow closer to failure.  If a bow can withstand 100,000 shots, then at 50,000 shots it is half way to failure.  Failure means many things:  set is one type of failure.

To put it simply, using a standard like Torges' is kind of like saying, "If you can park 100 fully loaded trailer trucks on that bridge for a day, it's good to go."  There is nothing wrong with that, as long as we're not talking about an old bridge.