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is speed forgiving?

1417 Views 24 Replies 16 Participants Last post by  BowTech One
all things being equal is a fast bow by todays standards going to be harder to be accurate with than a slow bow by todays standards. does speed accentuate any errors that a shooter may make in form or is it going to help because it is going to hit the target in shorter time
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all things being equal is a fast bow by todays standards going to be harder to be accurate with than a slow bow by todays standards. does speed accentuate any errors that a shooter may make in form or is it going to help because it is going to hit the target in shorter time
Ive went from a Switchback to a GT500 to a GX6. Your form is more critical to shoot the GX6 but its deadly accurate. IMHO I dont see that that the speed so much accenuates the errors as does the erganomics of the bow. The GT500 is just as shootable and forgiving as the Switchy.
 

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imo, the only thing that a fast bow is forgiving with is yardage judgement. They do make fast bows with a 7+'' brace height that is forgiving and tackdriving. But like the new crazy fast ones like the monster and the pse. I dont see how those can be forgiving at all as far as form or shooter error is concerned.
 

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I really don't think it's the speed of the bow but the design that makes it a accurate bow.If a shooter makes a error in his/her shot then it's still a error.Yes some bows are easier to hold BUT by some standards they are a speed bow cause they shoot over 300fps.Every year the mark that folks use to define a speedbow by how fast it shoots goes higher So I guess it's what do you define as a speed bow because I've never been able to get a good definition .Me ? I like the fastest bow that I can shoot accurately out in the woods with.
 

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Generally, speed bows are more critical to form - which is somewhat offset by the shorter length of time the arrow is still attached to the bow. I have found the Katera to be the exception to this "rule", though.

One example of the opposite phenomenon is my daughter's Mathews Genesis. This bow is so slow that I can't even get a reading on the chronograph. Maybe 100 fps. If your form is perfect, it will stack them in there pretty well. But just a little form cough, and you could miss the whole bag target at 25 yards. Great training aid.
 

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Discussion Starter · #6 ·
i kind of got in a argument with my brother about this so i was wondering if i was way off or if i had a credible argument. i was saying that todays speed bows are just as easy to shoot as yesterdays forgiving bows and he did not agree my argument was with no experience though that target shooters shoot a lower poundage bow but a light arrow to be steady with their shot but still maintain speed for error in yardage judgement or error in form and his arguement was that it would just get worse with speed am i wrong or was he so i can better understand this
 

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Speed has zero impact on accuracy. What has a major impact on accuracy is geometry, and speed bows generally have a set of dimensions that do not necesarily lend themselves to being stable to aim with. However, this is changing due to cam and limb design. Take the PSE xforce 7 for example. It has a rather helpful brace height of 7 inches, but add to that some fairly aggressive cams and limb orientation that allows for a big change in dynamic brace height (the brace height at full draw, per se), and you get a fairly forgiving bow. At an IBO of 340, you cant call it slow, and yet it shoots so well.

Still, you look at the cutting edge of speed, and youll still see the compromises seeping through, they take whatever advantage they can, and its all in the name of marketing.
 

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Speed has zero impact on accuracy. What has a major impact on accuracy is geometry, and speed bows generally have a set of dimensions that do not necesarily lend themselves to being stable to aim with. However, this is changing due to cam and limb design. Take the PSE xforce 7 for example. It has a rather helpful brace height of 7 inches, but add to that some fairly aggressive cams and limb orientation that allows for a big change in dynamic brace height (the brace height at full draw, per se), and you get a fairly forgiving bow. At an IBO of 340, you cant call it slow, and yet it shoots so well.

Still, you look at the cutting edge of speed, and youll still see the compromises seeping through, they take whatever advantage they can, and its all in the name of marketing.
 

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Generally, speed bows are more critical to form - which is somewhat offset by the shorter length of time the arrow is still attached to the bow.
If I understand you correctly, I think you've got this backwards. Speed bows normally have a brace less than 7", which actually keeps the arrow attached to the string longer, not shorter. More time on string = more energy transfer = more speed = more time for you to mess it up.

As for target shooters using less draw weight, several reasons I think. In spots and field competitions they are drawing their bow a LOT. In most 3D there is a speed limit which can easily be attained with todays carbon arrows and a good 50 or 60 lb bow. I'm sure there are other reasons as well.
 

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If I understand you correctly, I think you've got this backwards. Speed bows normally have a brace less than 7", which actually keeps the arrow attached to the string longer, not shorter. More time on string = more energy transfer = more speed = more time for you to mess it up.

As for target shooters using less draw weight, several reasons I think. In spots and field competitions they are drawing their bow a LOT. In most 3D there is a speed limit which can easily be attained with todays carbon arrows and a good 50 or 60 lb bow. I'm sure there are other reasons as well.

Actually, I did the math a couple of years ago. A fast 6" BH will have a longer length of travel with the arrow on string, but will do so in a short duration of time than a slower 7" BH.
 

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If you had 2 bows everything the same except for arrow speed. I think the faster one might be more forgiving. The quicker you get the arrow in the air. Gives you less time to mess it up while still on the rest and string.
 

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really like to see this math, how did you accurately measure the cam duration time?
My math skills are pretty good, and I think you got 'im here :)

The "Speed Bow=Less Accurate" myth, is pretty much just that, a myth.

Could be luck, but I have two Supertec's and two Turbotec's set up with four different arrows, at 4 different bow weights, that were the easeist bows to set up and tune, I've owned yet. All are rigged to come in at 290-300fps with selected shafts. I have a Protec that shoots as well, and a Vtec that shoots as well, but not any better.

Tuning makes a big difference, and arrows at the stiff end of the dynamic spine range seems to help. FOC/tip weight has little to do with anything as far as I can tell, as I use 75/85/100/125gr tips, and 2" vanes for everything. They all shoot the same. Same for Low brace height, notta bit of difference.

I see a lot of guys with opinions on all of the above, but it seems they usually own just one bow, shoot just one arrow, with one type of fletch, and a single tip weight. All of which are, of course, the "Best". Proving that those with the least amount of information, usually have the strongest opinions ;) but not much more.
 

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really like to see this math, how did you accurately measure the cam duration time?
Not completely sure what you mean by cam duration time.....I just kept it simple and based it upon the arrow leaving the string at BH using bows with an STS type device to limit string travel. Also assumed both bows had drop away rests so there was no rest contact after arrow left string. I'll see if I can dig up actual post.

Without getting into the math, I posed the question about forgiveness and had my theory hammered by target guys. I used my 28" DL as an example comparing my SBXT w/7.5"BH at 267fps VS my Vulcan w/6"BH at 300ish.

I converted all fps to inches/sec. Now that I understand archery a bit better I do realize I made a small error in accounting for time on string because I forgot to add 1 3/4" for the AMO DL. What I did was take 28"DL minus BH of 6 or 7.5 and considered that 22 or 20.5" as distance on string. I should have taken 1.75" off both of those measurements.

I then took the inches/sec of each bow X the total inches of travel of arrow on string and got a number of seconds on the string. The faster bow was on the string for more inches, but less time than the slower bow.....very basic and crude but seemed to make sense to me....less time on string is less time to bobble shot form was how I looked at it....and for me it has proven valid.

I have now jumped from a 6"BH bow to a 7"BH bow but they now shoot the same speed and the 7" is now even better and seemingly more forgiving because it is on string even a shorter amount of time.
 
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Speed

Do you need it? For 3 D tournaments I enjoy the extra speed. But, can I handle the speed? I practice with the bow at 70 lbs so I am used to holding the pressure at letoff. Both of my bows have almost zero recoil so that helps tremendously. But, if I ever need to come down from that weight in order to control the flight of the arrow I will. For every pound of bow weight you will lose or gain approximately 2 feet per second. I love a flatter trajectory for 3 D but does it help me to gain anything when going after big game? Not really. Google the kinetic energy calculator and start plugging in the numbers. For big game I want the maximum kinetic energy (energy in motion...the arrow) my bow will help me attain. I shoot a 379 grain arrow out of my bowtech captain at approximately 292-295 fps. My approximate foot pounds of energy is 74. If I use my 352 grain arrows I will attain a speed of approximately 302-305 fps but will lose approximately 1-2 foot pounds of energy. A higher foot pounds of energy will result in better penetration.
 

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Do you need it? For 3 D tournaments I enjoy the extra speed. But, can I handle the speed? I practice with the bow at 70 lbs so I am used to holding the pressure at letoff. Both of my bows have almost zero recoil so that helps tremendously. But, if I ever need to come down from that weight in order to control the flight of the arrow I will. For every pound of bow weight you will lose or gain approximately 2 feet per second. I love a flatter trajectory for 3 D but does it help me to gain anything when going after big game? Not really. Google the kinetic energy calculator and start plugging in the numbers. For big game I want the maximum kinetic energy (energy in motion...the arrow) my bow will help me attain. I shoot a 379 grain arrow out of my bowtech captain at approximately 292-295 fps. My approximate foot pounds of energy is 74. If I use my 352 grain arrows I will attain a speed of approximately 302-305 fps but will lose approximately 1-2 foot pounds of energy. A higher foot pounds of energy will result in better penetration.
When asking if you need speed....You should consider the question of Why wouldnt you want every advantage you can get when hunting big game animals. Yes your captain lost a little KE when shooting a lighter shaft. But the Captain is not a speed bow. Take a GT500 and shoot the same setup and gain speed plus KE, Plus its a 7 inch brace 35 inch ATA, very comparable to the specs of the Captain. You could make the bow just as quiet and its very accurate. So why wouldnt anyone want a faster bow????
 

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Not completely sure what you mean by cam duration time.....I just kept it simple and based it upon the arrow leaving the string at BH using bows with an STS type device to limit string travel. Also assumed both bows had drop away rests so there was no rest contact after arrow left string. I'll see if I can dig up actual post.

Without getting into the math, I posed the question about forgiveness and had my theory hammered by target guys. I used my 28" DL as an example comparing my SBXT w/7.5"BH at 267fps VS my Vulcan w/6"BH at 300ish.
The math does not work out like you anticipate.

The formula that you used (time = distance / velocity) only works if you have a constant velocity. You are also implicitly assuming that the accelleration on the arrow is zero - or you would use time = (final velocity - initial velocity) / acceleration. However, this equation assumes that acceleration is constant throughout the shot cycle - which is not the case. Because the acceleration changes during the shot cycle, the only way to accurately calculate the time is to use calculus and assume that velocity and acceleration are constantly changing.

And then there are the bow dynamics. If the draw force curve has a lot of acceleration in the early part of the shot cycle the arrow will leave the string faster than a bow shooting the exact same speed but with higher acceleration later in the shot cycle (a bow that is jumpy off the back wall vs one that has a "long" valley). Higher acceleration early means the arrow is traveling faster for a longer period of time (thus reducing the amount of time it takes to cover a given distance).

Of course, it would probably be more accurate/easier to get a high speed camera :wink:
 

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I would have to agree with difficulties in precisely quantifying the time span arrow is on the string, when being accellerated from a dead stop to 300 fps or so. But I can almost guarantee that an arrow that comes out of the bow at 320 is on the string less time than an arrow that comes out at 280. Whether the difference is 12% or not I don't know.
 
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