Torque vs Forgiveness
03-04-2002, 06:53 AM
#1
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Torque vs Forgiveness
I'm trying to better understand the effects of torque on a bow. When dealing with the effects of torque relative to brace height, I believe the relationship has to due with the time the arrow is in contact with the string after release, correct? If so, this factor would seem to affect torque from any dirction, making it a key component. It would seem all long draw archers have a built in disadvantage when it comes to accuaracy. Is that true?
As an example, is a person pulling a 21" powerstroke on a bow with a 7" brace, experiencing the same degree of torque as the same person pulling the exact same setup, but with a 21" powerstroke with an 8" brace? By "same setup", I mean same ATA, same grip, same components. By having the same person shooting both bows, I'm just trying to eliminate the variance between people's grip, and assume that the person would be gripping the same, even with a 1" longer draw.
The other major factor in forgiveness often mentioned is axel to axel length. It would seem to me that this would affect any torque applied to the grip that would cause the top or bottom limb to be pushed towards or away from the target and to any torque that would cant the bow, but not to torque that would cause the bow to spin on it's axis. Is this correct?
If I'm having more problems with left and right hits, than with up and down misses, it would seem to be a grip problem that would be affected slightly by a high brace height (shorter powerstroke) and not much at all by a longer ATA. Or, is canting the bow a major problem with left and right hits?
I'm trying to find out if certain misses can be helped more by either a shorter powerstroke or a longer ATA. Hope this makes a little sense.
As an example, is a person pulling a 21" powerstroke on a bow with a 7" brace, experiencing the same degree of torque as the same person pulling the exact same setup, but with a 21" powerstroke with an 8" brace? By "same setup", I mean same ATA, same grip, same components. By having the same person shooting both bows, I'm just trying to eliminate the variance between people's grip, and assume that the person would be gripping the same, even with a 1" longer draw.
The other major factor in forgiveness often mentioned is axel to axel length. It would seem to me that this would affect any torque applied to the grip that would cause the top or bottom limb to be pushed towards or away from the target and to any torque that would cant the bow, but not to torque that would cause the bow to spin on it's axis. Is this correct?
If I'm having more problems with left and right hits, than with up and down misses, it would seem to be a grip problem that would be affected slightly by a high brace height (shorter powerstroke) and not much at all by a longer ATA. Or, is canting the bow a major problem with left and right hits?
I'm trying to find out if certain misses can be helped more by either a shorter powerstroke or a longer ATA. Hope this makes a little sense.
03-04-2002, 07:44 AM
#2
Nontypical Buck
Join Date: Feb 2003
Location: CT, USA
Posts: 3,058
RE: Torque vs Forgiveness
Straightarrow,
you are very correct..depending on how the torque is appllied makes the difference
Higher brace bows that are torqued may or may not have as much impact on the severity of the mistake. Other factors come into play like riser style, for example. A high brace bow w/a deflex riser might not show the same amount of deviation as a bow w/ highly reflexed riser w/ similar brace height.
Brace height primarily effects "follow through"..how you react from the moment the string starts to come back to brace height. If your follow through is good and consistent, a low brace bow might not pose a problem. But you could also be torquing the grip or string at the same time and drop your bow arm straight down at the shot..a combination of mistakes.Or you could eb a "grip grabber" and cause the bow to torque at the shot..there's so many things..
A bow with more mass is more resistant to folow through and torque problmes generally. with folow through the heavy mass weight keeps one from moving the bow as much. Same w/ a long axle to axle, it helps stabilize the bow so that it's harder to move. A combination of heavy and long is doubly effective.
There are also other forms of torque. You could anchor improperly (usually too hard) and cause the string to come out the natural path of travel (this is where high letoff can hurt you,as it's harder to feel this mistake). Usually when you do this, you also end up torquing the grip as well causing a double mistake.
Then there is torquing or twisting the string with the release.This is one big reason why string loops and rope releases have become so popular: you can get away w/ a bit more of a mistake, but they are not without there own problems too. depending on where the grip is centered on the riser, it may cause up and down torque as well (putting too much pressure on the nock, and/or grip). Sometimes people just cannot get a good up/down paper tear with a loop, and this is often the culprit assuming it's not something technical like out of time cam/s or improper arrow spine.
There are a ton of variables involved..you can't always just say "ok..high brace, long length, and mass weight are best", but that is the best place to start for consistent accuracy 9 times out of 10.
JeffB
you are very correct..depending on how the torque is appllied makes the difference
Higher brace bows that are torqued may or may not have as much impact on the severity of the mistake. Other factors come into play like riser style, for example. A high brace bow w/a deflex riser might not show the same amount of deviation as a bow w/ highly reflexed riser w/ similar brace height.
Brace height primarily effects "follow through"..how you react from the moment the string starts to come back to brace height. If your follow through is good and consistent, a low brace bow might not pose a problem. But you could also be torquing the grip or string at the same time and drop your bow arm straight down at the shot..a combination of mistakes.Or you could eb a "grip grabber" and cause the bow to torque at the shot..there's so many things..
A bow with more mass is more resistant to folow through and torque problmes generally. with folow through the heavy mass weight keeps one from moving the bow as much. Same w/ a long axle to axle, it helps stabilize the bow so that it's harder to move. A combination of heavy and long is doubly effective.
There are also other forms of torque. You could anchor improperly (usually too hard) and cause the string to come out the natural path of travel (this is where high letoff can hurt you,as it's harder to feel this mistake). Usually when you do this, you also end up torquing the grip as well causing a double mistake.
Then there is torquing or twisting the string with the release.This is one big reason why string loops and rope releases have become so popular: you can get away w/ a bit more of a mistake, but they are not without there own problems too. depending on where the grip is centered on the riser, it may cause up and down torque as well (putting too much pressure on the nock, and/or grip). Sometimes people just cannot get a good up/down paper tear with a loop, and this is often the culprit assuming it's not something technical like out of time cam/s or improper arrow spine.
There are a ton of variables involved..you can't always just say "ok..high brace, long length, and mass weight are best", but that is the best place to start for consistent accuracy 9 times out of 10.
JeffB
03-04-2002, 08:11 AM
#3
Boone & Crockett
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RE: Torque vs Forgiveness
Straightarrow,
JeffB has this one pretty much covered but I did want to point out something...
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>I believe the relationship has to due with the time the arrow is in contact with the string after release <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>...
...."time" isn't so much of a factor as is distance. The longer the distance of the powerstroke the more chance there is for shooting errors to be magnified....so, yes, longer draw length archers do have a disadvantage in this regard.
JeffB has this one pretty much covered but I did want to point out something...
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>I believe the relationship has to due with the time the arrow is in contact with the string after release <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>...
...."time" isn't so much of a factor as is distance. The longer the distance of the powerstroke the more chance there is for shooting errors to be magnified....so, yes, longer draw length archers do have a disadvantage in this regard.
03-04-2002, 08:41 AM
#4
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RE: Torque vs Forgiveness
PA,
I thought about the time vs distance thing when determining torque while the arrow is on the string and it occured to me, that if the arrow was moving so fast that it came off the string almost instantly, there would be less torque transferred to the arrow. If the bow is twisting from torque while the string moves twice as fast, isn't the distance of torque also halved?
I thought about the time vs distance thing when determining torque while the arrow is on the string and it occured to me, that if the arrow was moving so fast that it came off the string almost instantly, there would be less torque transferred to the arrow. If the bow is twisting from torque while the string moves twice as fast, isn't the distance of torque also halved?
03-04-2002, 09:03 AM
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RE: Torque vs Forgiveness
Torque and brace height aren't necesarily related are they? One issue is erors that lead to inaccuracy, these might be things like droping the arm early in follow through, or torquing the handle.
The second issue is how those erors are showing up in your results on target, and what the bow does to mitigate or propogate those results. So in this case a low brace height bow might still be pushing the arrow when you drop your hand or torque your riser - bad. In that sense the low brace height is really a time issue, like locktime in a gun. Maybe you goof the shot early, but if you goof it later, and it is still on the string, there is going to be some effect. To me, time affects us all the same whether we are long draw or not. On the other hand a longer draw person may be able to use a heigher brace height and still get decent performance, where the shorter draw length person would be forced into a lower brace height bow.
Another issue is that with a low brace height bow, or an overdraw, the distance between the string and the rest is shorter. Whether that maters or not I don't know, but it could sort of wedge the arrow off course if the arrow is in contact with the rest at all.
There is also the bows delta form. A high brace height bow may have a more stable geometry due to the more arched shape it has.
Overall, I think we have to be careful to put too much emphasis on brace height. What kind of a curve is it? we know at low levels it makes a bow hard to shoot, Most shooters would notice the difference between 5.5 and 6.5", but is there a big difference between 7 and 8"? The mathews C2 is very easy to shoot accurately, and so is the rival pro, the former has a 7" brace height, and the pro has an 8" brace height. I can't really tell the difference, overall, I prefer the C2.
The second issue is how those erors are showing up in your results on target, and what the bow does to mitigate or propogate those results. So in this case a low brace height bow might still be pushing the arrow when you drop your hand or torque your riser - bad. In that sense the low brace height is really a time issue, like locktime in a gun. Maybe you goof the shot early, but if you goof it later, and it is still on the string, there is going to be some effect. To me, time affects us all the same whether we are long draw or not. On the other hand a longer draw person may be able to use a heigher brace height and still get decent performance, where the shorter draw length person would be forced into a lower brace height bow.
Another issue is that with a low brace height bow, or an overdraw, the distance between the string and the rest is shorter. Whether that maters or not I don't know, but it could sort of wedge the arrow off course if the arrow is in contact with the rest at all.
There is also the bows delta form. A high brace height bow may have a more stable geometry due to the more arched shape it has.
Overall, I think we have to be careful to put too much emphasis on brace height. What kind of a curve is it? we know at low levels it makes a bow hard to shoot, Most shooters would notice the difference between 5.5 and 6.5", but is there a big difference between 7 and 8"? The mathews C2 is very easy to shoot accurately, and so is the rival pro, the former has a 7" brace height, and the pro has an 8" brace height. I can't really tell the difference, overall, I prefer the C2.
03-04-2002, 10:22 AM
#6
Boone & Crockett
Join Date: Feb 2003
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RE: Torque vs Forgiveness
Straightarrow,
The reason I brought up the issue of distance versus time on different brace height bows is because if you do the actual math then the time issue isn't quite as prominent as the distance is.
What I am trying to say is that if you do the math and compare a 7 inch brace height bow shooting an arrow at 290 fps with a 6 inch brace height bow shooting an arrow at 310 fps then you will see that the actual time that both stay on the string is very, very close. The reason for this being that the shorter brace height bow, though it has a longer powerstroke, pushes the arrow faster over that distance.....
...so the "time issue" isn't so much important as the distance of the powerstroke.
Ossage,
I would tend to agree with you to some extent....
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>Overall, I think we have to be careful to put too much emphasis on brace height. <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
...there are many other factors that affect the "forgiveness level" of any given bow...but I, personally, feel that brace height is probably the biggest.
Edited by - PABowhntr on 03/04/2002 11:26:02
The reason I brought up the issue of distance versus time on different brace height bows is because if you do the actual math then the time issue isn't quite as prominent as the distance is.
What I am trying to say is that if you do the math and compare a 7 inch brace height bow shooting an arrow at 290 fps with a 6 inch brace height bow shooting an arrow at 310 fps then you will see that the actual time that both stay on the string is very, very close. The reason for this being that the shorter brace height bow, though it has a longer powerstroke, pushes the arrow faster over that distance.....
...so the "time issue" isn't so much important as the distance of the powerstroke.
Ossage,
I would tend to agree with you to some extent....
<BLOCKQUOTE id=quote<font size=1 face='Verdana, Arial, Helvetica' id=quote>quote:<hr height=1 noshade id=quote>Overall, I think we have to be careful to put too much emphasis on brace height. <hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face='Verdana, Arial, Helvetica' size=2 id=quote>
...there are many other factors that affect the "forgiveness level" of any given bow...but I, personally, feel that brace height is probably the biggest.
Edited by - PABowhntr on 03/04/2002 11:26:02
03-04-2002, 10:36 AM
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RE: Torque vs Forgiveness
PA you may well be right, as I mentioned before, all my personal bows have had brace height of 7 or more inches so I don't know as much about this as some do. But a key question i asked is about the curve. Are there diminishing returns? Mathews actualy moved from 8" to 7" on their key target bow last year. What that tells me is that they figure that on an already forgiving bow even target shooters generaly wouldn't object to the lowered brace height, presumably because the difference wasn't all that apparent. Would there have been a perceptible advantage to going in the opposite direction say 9". I personaly doubt it, but don't know. My best guess is this only bites you when pushed it to an extreme.
03-04-2002, 10:53 AM
#8
Join Date: Feb 2003
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RE: Torque vs Forgiveness
There are some topics I think I know as much about as most people, but this isn't one of them, so excuse me gassing on, but i would like to learn something.
What I mean by "the curve" is if we plotted brace height to forgiveness, I don't think the curve would be a straight line. The yikes! factor seems to hit in the 6" range. If one considers the length of the powerstroke, which is the locktime factor from 7-6" on a 20-21" stroke we are only seeing a 5% change which doesn't account for the yikesness of what is happening. On the other hand it is a 16% change in brace height, which is significant, but perhaps still understated. Part of what is going on is that there are multiple factors here. They don't make a C2 with a 5.5" brace height, and how nice would a Gforce be to shoot even with an extra inch of brace height. But nonetheless based on the numbers the culprit seems more in the fact the brace height was lowered than the power stroke was lengthened (did I say the opposite above, well that's what you get with a lot of caffeine). That being the case, it seems to me that it is either the allignment thing, in which case there wouldn't be any problem with a drop away rest (someting I haven't heard said, hey science is difficult). Or maybe it is biomechanical, the brace height, and the arrow leaving the string coincide with something like the wrist joint, and its movement. I'm bailing as fast as I can here...
What I mean by "the curve" is if we plotted brace height to forgiveness, I don't think the curve would be a straight line. The yikes! factor seems to hit in the 6" range. If one considers the length of the powerstroke, which is the locktime factor from 7-6" on a 20-21" stroke we are only seeing a 5% change which doesn't account for the yikesness of what is happening. On the other hand it is a 16% change in brace height, which is significant, but perhaps still understated. Part of what is going on is that there are multiple factors here. They don't make a C2 with a 5.5" brace height, and how nice would a Gforce be to shoot even with an extra inch of brace height. But nonetheless based on the numbers the culprit seems more in the fact the brace height was lowered than the power stroke was lengthened (did I say the opposite above, well that's what you get with a lot of caffeine). That being the case, it seems to me that it is either the allignment thing, in which case there wouldn't be any problem with a drop away rest (someting I haven't heard said, hey science is difficult). Or maybe it is biomechanical, the brace height, and the arrow leaving the string coincide with something like the wrist joint, and its movement. I'm bailing as fast as I can here...
