What would cause this..

[pavan]

Is it possible for a recurve limb to collapse side ways while being drawn?  Even if there is a bit of draw hand torque, I cannot see a limb buckling sideways and dumping the string.  Unless the loops were way to big for the limbs and it half jumped off on the previous shot.

[McDave]

I’ve seen it happen on a friend’s recurve.  47# 62” one piece recurve made by a well known bowyer.  Can’t remember anything about the string loops, but it was the same string it came with and I don’t remember anything unusual about the string. He described the problem to me, and the first thing I did was to string the bow and check for limb twist.  No limb twist evident at brace height.  Then we went shooting together and about half way around the course the string popped off as he was drawing the bow.  I know he was torquing the string because I had tried a half dozen times to get him to quit doing that, but he didn’t seem to get the concept, so I pretty much gave up.  After this happened, I demoed for him how I could make the string move out of the string grooves by drawing slowly with string torque, stopping short of drawing it until the string popped completely off the bow.  Funny thing is it never did show up at brace height, although I assume it eventually would have.

It is more common with the kids I teach with Genesis compound bows.  If a kid torques the string on a Genesis very much, it’s going to pull the string out of the pulley.  Probably has happened 4-5 times over the years.

[buckeyebowhunter]

Thanks for the replies guys. McDave i am almost certain it is from torque. No way would i have not seen the string coming out of the grooves on previous shots. As I mentioned this is one of the lightest bows i own on top of that the limbs on it are extremely skinny at the ends. I still would have never imagined i would torque so much that it would dump the string. I did end up calling black widow and they made a note of what happened in their files but said as long as the limbs aren't twisted there's really nothing else they can say but if anything else happens they said to give them a call. I will take the blame for this one but if it does it again it's going back to Nixa. I think what puzzles me the most is that I've owned widows for years and shot many that weren't mine and never experienced this 

[pavan]

If draw hand torque can do that, for me, I would be a bit scared of it when hunting.  I am not always very delicate when I take hunting shots.

[McDave]

I've only seen this happen with two recurves.  I assume it requires a combination of string torquing with certain recurves that have a low resistance to lateral limb tip movement. In the example I mentioned above, there was no persistent limb twist, meaning that the limb tips evidently sprung back into alignment after dumping the string.  Given the large number of people I observe torquing the string, I would assume most recurves are not likely to have to this problem.  I can't imagine this happening with a longbow, although anything is possible, I guess.

[KentuckyWolf]

Ever see Ken Becks demo on string torque? He used 7# limbs (yes a widow with special made 7 lbs limbs) to show what happens when you twist the string hand and /or the bow (bow hand) out of alignment.

Never saw him release from the torqued position....but I bet it very well would pop the string off.

I bet any recurve would with enough torque. Longbows might be harder to do...more resistance to torque but possible.

[pavan]

Many moons ago i had a very lean tipped target bow.  I could not shoot it with a glove, a little better with a Kantpinch, but with the Wilson Straptab that bow shot 290s indoors for me. At the time I thought the variance was vertical, could have been a nasty roundhouse torque as well.  I have had two Bear takedowns try to eat me alive, magnesium risers blowing up, but I have never had a string jump off.  If one has a very nice bow that is prone to something like posted above, what does one do about it?

[buckeyebowhunter]

Pavan, what worries me the most is the hunting situation.  Like someone previously mentioned perfect form isn't always the greatest or 100% applicable when a hunting shot presents itself. If something like this happens on a animal I'm not sure i could forgive myself or the bow. Hopefully it was a fluke! I'm going to keep shooting and see what happens. Since this happened I've probably put 100 arrows through it with no issues.

[pavan]

The one thing that i noticed looking at old pictures of me shooting way back then, I tried to have a longer draw than i do now.  From what i see now that i did not see then is that I was leaning back away from the shot and at anchor I was ring finger heavy and my palm was turning down at at anchor.  That could cause some serious string torque.  I have seen others display this palm turning downward with others going for as long a draw as they can stretch to.  Of course, I cannot say one way or the other in your case, but it may be worth checking.

[McDave]

Pavan, what worries me the most is the hunting situation.  Like someone previously mentioned perfect form isn't always the greatest or 100% applicable when a hunting shot presents itself. If something like this happens on a animal I'm not sure i could forgive myself or the bow. Hopefully it was a fluke! I'm going to keep shooting and see what happens. Since this happened I've probably put 100 arrows through it with no issues.

Fortunately, the worst that would happen is that the animal would run away, since no arrow is going to leave the bow if this happens.  I could forgive myself for that a lot easier than I could forgive myself for wounding an animal and not being able to find it.

In addition to what Pavan says, I frequently open my bow hand slightly at full draw and wobble my string hand back and forth slightly.  If the bow doesn’t show any tendency to straighten up, and my wobble transmits itself freely to the bow, then I know I’m not torquing anything.

[buckeyebowhunter]

McDave, that's a good point. My point was simply that getting close to the animal is what we work for and only for your equipment to malfunction would be heartbreaking. Like I said I'm not blaming my bow in this instance but I also have a tough time blaming myself entirely when I've never had it happen on any other bows. The hunting thing is kind of a tangent from my original post so I'll end it on that note. Ultimately it could be a form issue and I appreciate the input from everyone. 

[McDave]

Sometimes these things can be a blessing in disguise.  If you learn to shoot without torquing the string, you will be a much better shot.  I've said the same thing to people about cutting their tabs shorter to the point where their fingertips show above the tops of their tabs.  If you learn to shoot by relaxing your fingers and letting the string push them aside rather than trying to open your fingers, you will be a much better shot.  The sting on your fingertips if you forget is just a reminder.  Unfortunately, having your bow unstring itself is a bit more of a reminder than most of us would want to have!  If yours is a bow that is ultra-sensitive to torquing, it is important to keep the limb tips in alignment at all times.  Check it every time you string the bow for sure, and every time you take it out to shoot for a while, until you are sure it is holding its alignment.  Something like this might help you to keep it in perfect alignment:  http://www.lancasterarchery.com/beiter-limb-tip-line-gauges.html

[buckeyebowhunter]

Excellent advice. I appreciate all the input guys!