Primitive Archer
Main Discussion Area => Bows => Topic started by: bradsmith2010 on April 26, 2017, 11:10:07 am
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I have seen this mentioned on some post and was wondering,, in your opinion how much faster is a recurve,,??
10 fps 20 fps,, what could be expected,, draw weight, arrow weight being equal,, 10 gpp,, thanks in advance,, B
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I would say 10-15.
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I am more interested what happens with speed when you put recurves on longer bows, for example 66" I will soon build
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Like any bow, its all about set, strain and design. An over stressed recurve wont shoot faster than a thoughtfully built straight bow.
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I can't tell you how many times I have built bows and decided to recurve them instead of thinning down the tips only to have them take additional set and wind up with the tips in the same place they were before I recurved. It all need to be built in from the start and even then doesn't always come out as planned.
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Its really impossible to answer because the question is flawed. A well designed recurve wont shoot any faster than a well designed straight bow. Recurves are a design option to use when the limitations of the stave would benefit from them.
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Generally I wouldn't say a potential recurved stave has limitations.
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Generally I wouldn't say a potential recurved stave has limitations.
Stave length vs desired draw length comes to mind.
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I agree with Pearl in that a well designed straight limb will outperform a poor designed recurve. I will also say that it's harder to pull off a well designed recurve than a straight limb bow, therefore most straight limb bows perform just as well as or better than most recurves. However, I do not agree with the statement that a well designed straight limb will outperform a well designed recurve. If a recurve is designed well then mechanically and theoretically it SHOULD outperform a straight limb or else it's not well designed. This is due to the fact that recurves should have a fatter force curve for the same target weight. Therefore more stored energy and faster speeds.
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Perhaps the limitations are placed on the stave by us according to what we want to make it do.
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Generally I wouldn't say a potential recurved stave has limitations.
Stave length vs desired draw length comes to mind.
and material. Again it comes down to designing it well to handle the extra stress. If not accounted for = poor design = recurve < straight limb. If accounted for recurve > straight limb.
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I agree with Pearl in that a well designed straight limb will outperform a poor designed recurve. I will also say that it's harder to pull off a well designed recurve than a straight limb bow, therefore most straight limb bows perform just as well as or better than most recurves. However, I do not agree with the statement that a well designed straight limb will outperform a well designed recurve. If a recurve is designed well then mechanically and theoretically it SHOULD outperform a straight limb or else it's not well designed. This is due to the fact that recurves should have a fatter force curve for the same target weight. Therefore more stored energy and faster speeds.
The fd curve may be affected by fecurves depending on stave length and draw length. But i believe the limitations are that a recurve rquires much more tip mass.
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I am quite sure a well designed recurve will beat a well designed straight bow every time. The primary thing that boosts the speed is how far the tips are behind the back of the bow, a reflexed straight bow if there is such a thing will perform very well but still behind the recurves. I personaly do best with semi recurves or reflex deflex bows just because I can do a better job on them. A good reflex defelx will give a good recurve a run for its money.
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Y'all have still left out a variable that has more to do with performance than the other factors mentioned. Recurves are generally shorter than longbows.
In fact the biggest and first reason for recurved tips was to keep the string on a short bow.
I suspect all elements being equal INCLUDING length, long bows will match recurves.
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I am quite sure a well designed recurve will beat a well designed straight bow every time. The primary thing that boosts the speed is how far the tips are behind the back of the bow, a reflexed straight bow if there is such a thing will perform very well but still behind the recurves. I personaly do best with semi recurves or reflex deflex bows just because I can do a better job on them. A good reflex defelx will give a good recurve a run for its money.
This is where I am on this. The stadic bows I have built was not that impressive . I have only built 3 so mine may not be a good judge of performance. This was also pryer to me useing d97 string. I am speaking of selfbows here also no sinue or any other backings. Arvin
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Generally I wouldn't say a potential recurved stave has limitations.
Stave length vs desired draw length comes to mind.
Would you recurve it if it was too short for the desired draw length?
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Generally I wouldn't say a potential recurved stave has limitations.
Stave length vs desired draw length comes to mind.
Would you recurve it if it was too short for the desired draw length?
Beyond a doubt. So long as I have the desired width.
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Y'all have still left out a variable that has more to do with performance than the other factors mentioned. Recurves are generally shorter than longbows.
In fact the biggest and first reason for recurved tips was to keep the string on a short bow.
I suspect all elements being equal INCLUDING length, long bows will match recurves.
Again it depends on the length. This isn't true at all lengths. Between a straight limb and a recurve at equal lengths greater than 70"+, the straight limb would probably outperform just cause the recurve might not get string let off at a 28" draw length. But if you had a straight limb and a recurve at an equal length less than 60" then the recurve will out perform the straight limb by far (as lomg as its designed well).
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Generally I wouldn't say a potential recurved stave has limitations.
Stave length vs desired draw length comes to mind.
Would you recurve it if it was too short for the desired draw length?
Beyond a doubt. So long as I have the desired width.
Why if it makes no difference?
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Ill simplify all this. Anything I build is faster than anything you guys build. My straight limbs are faster than anybody's recruves and my recurves are faster than anybody's straight limbs. You cant win.
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I understand that shorter bows gain a advantage from the string angle being better with the recurves but the part I can't wrap my mind around is if you have 2 bows identical in every way reflex,draw length & weight but one is recurved & one is strait limbed say the bows are 67 in. @28 in. Draw ,is how the recurve would be faster , to me in those hypothetical bows it seems to me the strait limbed would be faster with the tips needing less mass & at that length & draw the string angle would not be a critical isue ? It seems to me tip & bow limb mass would be the speed factor ?
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Recurved tips being heavier is an old wives tale.
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Ill simplify all this. Anything I build is faster than anything you guys build. My straight limbs are faster than anybody's recruves and my recurves are faster than anybody's straight limbs. You cant win.
Well hell, I give up then. I will just mail my staves off to you then.
Sarcastic humor of course, mine are clearly faster than yours. You just make em more pretty than me. ;)
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Recurved tips being heavier is an old wives tale.
Im listening.
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Generally I wouldn't say a potential recurved stave has limitations.
Stave length vs desired draw length comes to mind.
Would you recurve it if it was too short for the desired draw length?
Beyond a doubt. So long as I have the desired width.
Why if it makes no difference?
Too broad a brush there. It makes a difference in design limitations. Recurves aid in longer draws for shorter staves. I dont believe that shorter bow with recurves will outperform a longer straight bow of same stats.
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Recurved tips being heavier is an old wives tale.
I would agree. I think people tend to overbuild their static recurve tips. If you think about it, a proper tiller for even a straight bow has the last 6 inches or so being static to avoid whip tiller. Really it doesn't have to be much thicker than that. I think people are so paranoid about dynamic recurves that they think that they need no movement whatsoever to make a static, when really just barely stiffer than dynamic might work with just the slightest of movement. But i'm no expert and would like to know how others reduce their mass on static tips.
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Gfugal, i dont think you are wrong. I more than likely overbuild my recurves.
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Ok I can see why I was confusesd,, I was just thinking Marc said a recurve will outshoot a straight tip by a wide margin,,,the only number put out seems to be 10 to 15 fps,, faster,, but alot of great minds dont seem to agree,, Since Marc has built some pretty fast recurves i was hoping he would chime in,, but the info and discussion has been great,, I am still scrataching my head,, but really enjoy thinking about this,, and plan to incorportate some things into my next build,, :NN
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Too broad a brush there. It makes a difference in design limitations. Recurves aid in longer draws for shorter staves. I dont believe that shorter bow with recurves will outperform a longer straight bow of same stats.
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So you want a longer draw from the short stave even if it gains you nothing?
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PatM, are you bustin my balls for fun or what? I must be missing the point you are driving at, because I know you are experienced.
Im stating this. A properly designed recurve that is 48 inches ntn will match a straight bow 62 inches ntn assuming draw length and weight are equal. Tje only reason I would recurve the 48 incj bow is to gain draw length off it because its too short for a straight bow at 26" draw. I dont know how else to put it? :-\
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Too broad a brush there. It makes a difference in design limitations. Recurves aid in longer draws for shorter staves. I dont believe that shorter bow with recurves will outperform a longer straight bow of same stats.
So you want a longer draw from the short stave even if it gains you nothing?
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What gains me something is a longer draw and longer draws will gain you stored energy. It also gains you less stack, but a longer bow does the same. So here the discussion turnes to ways to get longer draws from a set stave, and recurving is a way to do it. So is a bendy handle.
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Tje only reason I would recurve the 48 incj bow is to gain draw length off it because its too short for a straight bow at 26" draw. I dont know how else to put it? :-\
You gain the draw length because the string will stay on with the recurves, right? No other reason?
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Too broad a brush there. It makes a difference in design limitations. Recurves aid in longer draws for shorter staves. I dont believe that shorter bow with recurves will outperform a longer straight bow of same stats.
So you want a longer draw from the short stave even if it gains you nothing?
What gains me something is a longer draw and longer draws will gain you stored energy. It also gains you less stack, but a longer bow does the same. So here the discussion turnes to ways to get longer draws from a set stave, and recurving is a way to do it. So is a bendy handle.
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So you think the short stave has more potential if recurved?
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No and yes :D If you want a 20 inch draw on a 48 inch bow, then no. If you want a 26 inch draw then yes. It has more potential, as in, potential energy due to longer draw. But if you compare a short draw bow to a long draw bow of the same draw weight, it becomes an unfair comparison and I am trying very hard to avoid that pitfall in this conversation.
DC, that is the main reason I recurve, to gain efficient draw length. By that I mean two bows can draw the same distance but one stacks and the other doesnt. Stack makes those last inches that stack occurs less effecient in energy storage than otherwise.
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But if recurving gets you more out of a short stave why wouldn't that just scale up?
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Because a 68 imch bow wont be drawn far back enough to take advantage of the recurves. Tjere is a draw lengtj to bow length ratio that recurves work well in. The benefit is not linear.
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I meant within the rate you are talking about.
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Im sorry, I dont understand?
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I meant if recurving lets you get so much out of a short stave then surely even slightly longer staves have more in them.
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Sure they may, but only if the design you want to build requires more out of the stave than it wants to give you straight.
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One thing I don't think anyone's mentioned yet is stability and accuracy. The short recurved bows I've built (bending through the handle, and 54" ntn or less) shoot really fast, but they're harder to control. That's why I like a nice marriage of both worlds- a 64-65" ntn static-handle recurved bow with short sharp-bending static tips.
I also have to say, I'm kinda obsessed with Marc's bows (yes, If there were a Marc fan club I'd run for president). I just feel like he's got a lot of things figured out so a lot of times I go off his example. He makes longer static recurves, deflex-reflex, and ALBs.
P.S. Sorry Brad, I know the post was about what's faster. I got a little off topic.
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I am equally terrible at shooting a short or long bow. There is no difference to me.
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It seems worth noting that nobody has posted the results of careful experiments....So, how many angels do YOU think can dance on the head of a pin at the same time????
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Marc has tested this. Give him some time to chime in.
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I seem to remember that Mojam results favor straight limbed bows.
I think TBB 4 has some results.
Jawge
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George, the Mojam results would not hold up to today's bows and arrows. The fastest one would only be considered average by todays standards.
Jim Davis, I used a shooting machine to test hundreds of bows. The fastes bow I tested was a recurve by Mark St Louis at about 190 fps average for 6 shots. fastest D/r Bow I tested was one of my own at 188. Fastest straight bow I have tested is about 175. These were all wood or bamboo backed bows.
Recurves consistently average higher than anything else. One of the reasons they have not done as well in recent flight shooting I think is that not many of them have competed. The recurves I have made for flight shooting were extremely fast but I never got any good distance out of them because of poor arrow flight. Not the fault of the bow. I have always done best with very conservative designs primarily because I get beter arrow flight out of them for reasons I have yet to figure out.
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My experiences are in line with what Steve said. My best straight limb bows have shot in the mid 170's and my best recurves in the mid to high 180's. That means that Pat's claims are essentially right, 10 ~ 15 fps faster. I certainly would be interested to know if someone has gotten better than 180 fps with a straight limb bow, this of course being tested with 10 GPP arrows and a true 28" draw.
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Not everything takes precision experimenting, sometimes consistant results in comparision through experience is good enough.
Aaannnddd it would seem precise experiments done by experts disagree with me. I still hold my ground. Thing of it is, even though I cant prove it, i belisve I have hit 188 with a straight bow.
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Steve, so what are you saying the recurves are better now-a-days?
Then, why would the straight limbers not get better too?
Seems to me I remember a certain straight limbed bow hitting 180 fps back then.
Check it out in TBB4.
It's too late for me to do so and you're younger than I am and 3 hours behind. :)
Jawge
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That bow was drawn to 30 I believe.
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No, 28" for all in the Mojam study.
Darn if that bow don't beat all. It was pecan too. TBB 4. :)
Jawge
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Do we have any flight speeds for horn bows? Or was it specifically reserved for self or wood only bows? The reason i bring it up is because of the ancient turkish flight contests. Surley they know what they were doing too and i have a hard time imagining them shooting anything other than an asiatic style horn bow, which have siyahs which are like recurves. Granted they probably didn't stick to 10 gpp or 50 lbs at 28". But getting the supposed 1/2 mile distance is no small feat no mater the rules.
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Steve, so what are you saying the recurves are better now-a-days?
Then, why would the straight limbers not get better too?
Seems to me I remember a certain straight limbed bow hitting 180 fps back then.
Check it out in TBB4.
It's too late for me to do so and you're younger than I am and 3 hours behind. :)
Jawge
George, I believe I was the one that tested the pecan bow of Bakers you are referring to , It was drawn about 31" and pulling around 58# I believe with a 500 grain arrow so it would not have been a valid test for 28" 10 grains per pound.
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Do we have any flight speeds for horn bows? Or was it specifically reserved for self or wood only bows? The reason i bring it up is because of the ancient turkish flight contests. Surley they know what they were doing too and i have a hard time imagining them shooting anything other than an asiatic style horn bow, which have siyahs which are like recurves. Granted they probably didn't stick to 10 gpp or 50 lbs at 28". But getting the supposed 1/2 mile distance is no small feat no mater the rules.
The bow that set that record was reported to be about 150# draw weight. Most of Adams Karpowitz bows test out a tad better than most well made all wood recurves. The few I have personally tested were on a par with very well made wood self bows.
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Brad
Thanks for keeping the recurve questions alive. There have been a few related threads lately, and this observation of Steve's helps answer a few things, for me anyway.
I can't tell you how many times I have built bows and decided to recurve them instead of thinning down the tips only to have them take additional set and wind up with the tips in the same place they were before I recurved.
must be a little extra wood storing some additional energy with the design difference.
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Do we have any flight speeds for horn bows? Or was it specifically reserved for self or wood only bows? The reason i bring it up is because of the ancient turkish flight contests. Surley they know what they were doing too and i have a hard time imagining them shooting anything other than an asiatic style horn bow, which have siyahs which are like recurves. Granted they probably didn't stick to 10 gpp or 50 lbs at 28". But getting the supposed 1/2 mile distance is no small feat no mater the rules.
Adam Karpowicz has speed numbers if you do a search.
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Yes I do believe you were the one testing that bow Steve.
Here is a link to Adam's Turkish bow tests httpwww.atarn.org/islamic/akarpowicz/turkish_bow_tests.htm
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I've peeked at that.He needs someone strong enough to shoot his heavier bows.Quite impressive numbers though.
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Baker's pecan bow was 71# at 28" and shot 184 fps.
The poundage was more than I figured but still pretty good.
His 50 # at 28" pecan shot 164 fps. TBB4 P 110.
Mattingly's, Lord rest him, osage recurve shot 57# at 28" shot 173 fps.
Jawge
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George, keep in mind those tests were done with 500 grain arrows, nothing like 10 grains per pound. I don't have tb4 here with me but I thought his Pecan bow that won the contest was 47# and shot at 164.
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Also keep in mind numbers from a machine shot bow compared to a finger shot bow will be different.
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Also keep in mind numbers from a machine shot bow compared to a finger shot bow will be different.
As long as all bows are shot either way it's a fair test.
Jawge, a 71 pound recurve will crack 200 with 500 grain arrows.
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Also keep in mind numbers from a machine shot bow compared to a finger shot bow will be different.
Yes, on the average about 7 fps slower. Knowing Tim and how he shoots his pecan bow would have proably hit about 170 had it been shot from a machine. In my case and a few others who have practiced can artificially boost sppeds by using an active release method. I kind of trained myselt to calibrate my release to a machine release. Not really all that hard if you are testing enough.
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So using the virtual mass badger explained once. I did my best the theorize what those Asiatic bows would be shooting 10 gpp using the closest arrow weight above the desired arrow weight. They are in the order they are presented on the website.
178 fps @ 28"
186 fps @ 27.5"
187 fps @ 27.9"
190 fps @ 29.9"
187 fps @ 28"
179 fps @ 28"
193 fps @ 30"
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To be fair all bows should be excersized the same before shooting.Most times 3 full draw pulls before shot through the chrono I feel anyway.The last 4 to 5 inches of draw I shoot gets pulled fast and released instantly for the best results I get.A snap shot I guess I call it.3' in front of the chrono.I don't trust myself shooting through it at 20 yards or even 10 yards.Afraid I might kill my chrono.....lol.Do it enough and it becomes a habit even while hunting.
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So using the virtual mass badger explained once. I did my best the theorize what those Asiatic bows would be shooting 10 gpp using the closest arrow weight above the desired arrow weight. They are in the order they are presented on the website.
178 fps @ 28"
186 fps @ 27.5"
187 fps @ 27.9"
190 fps @ 29.9"
187 fps @ 28"
179 fps @ 28"
193 fps @ 30"
Those look pretty accurate
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I haven't heard hard data, except from Marc, yet and remember my roots which is science. Controlled testing... somebody watching for over draws... measuring arrow weight. Repeatable results with more than one person. Same type of release. Bow size.
So lacking the above let us keep the dialogue going.
What is it about a static recurved bow that you all think makes it shoot faster than straight limbed bows. Is it the decreased string angle?
Jawge
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If you bend something to effectively shorten it the object can be swung faster. A static has its total length effectively shortened.
Plus I think the leverage advantage allows the end draw weight to register less than is indicated. Similar to using a lever to lift a heavy object. A static shoots like a heavier straight bow. Much heavier.
I do think a static stresses the material more uniformly and to a greater degree.
Back in the day people flight shot straight bows over 400 yards but they shot statics well over 500 yards.
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I have only from time to time access to a chrony. But was able to test out my best bows, 10ggp, 28"
Got average of 185 for static recurves and about 170 for straight (with reflex and changing cross section) bows.
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A static recurve changes how the energy is stored in the bow making more of it available at the beginning of the power stroke, sort of like how a wheel-bow stores its energy
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Yes, agree that recurving would account for early energy storage as would reflexing.
Jawge
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OK I'll say this anyway in comlpete honesty.A straight limbed sapling flipped tip[not really a recurve] limbs a bit slightly reflexed bow[total on bow 2.5" NTN]I showed some time ago called a wiggle handled osage rawhide backed shot into the low 180's /high 170's with a 10 grain arrow when fresh before 200 arrows through it.48# @ 28".My arrows can't be overdrawn.The nock throat and back end of field point are exactly 28".Bow is 66.5" NTN.It's had a good 1000 arrows through it already for sure now.I imagine it still shoots into the low to mid 170's for sure yet.
Not near all my self bows shoot like that though but some others do too.A slightly D/R KCT straight limbed self bow with 10" stiff levers 68" TTT shoots those numbers too with a 10 grain arrow.
Seems a fat FDC is essential for extra speed.
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Yes and outlier statics will shoot correspondingly faster as well.
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Yes and outlier statics will shoot correspondingly faster as well.
What are outlier statics?
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Seems a fat FDC is essential for extra speed.
Indeed! A real fat curve isn't completely necessary for fast bow, but it absolutely is for record setters.
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Yes and outlier statics will shoot correspondingly faster as well.
What are outlier statics?
Outlier as in above and beyond the norm.
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I realized that from shooting a composite bow I made some time ago.Getting the most fps out of a pound of draw weight.
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Yes and outlier statics will shoot correspondingly faster as well.
you are referring to static recurves when you say "statics", Pat?
I think some of the mechanics described in this thread could be be for straight limbed statics, and then there are additional benefits for recurving the static tip? (most likely having the tips further forward than in the straight version?)
the string angle thing being a different effect, most useful for shorter bows?
too much being discussed all at once possibly?
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Yes. Apart from stiff handles I can't imagine what else it would apply to.
I can't honestly tell a difference between an angled or a curved static tip if the tips end up in the same relative position and the portion is the same length.
It may register on a measured force draw but the feeling to the hand and arm would be hard to discern.
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OK I'll say this anyway in comlpete honesty.A straight limbed sapling flipped tip[not really a recurve] limbs a bit slightly reflexed bow[total on bow 2.5" NTN]I showed some time ago called a wiggle handled osage rawhide backed shot into the low 180's /high 170's with a 10 grain arrow when fresh before 200 arrows through it.48# @ 28".My arrows can't be overdrawn.The nock throat and back end of field point are exactly 28".Bow is 66.5" NTN.It's had a good 1000 arrows through it already for sure now.I imagine it still shoots into the low to mid 170's for sure yet.
Not near all my self bows shoot like that though but some others do too.A slightly D/R KCT straight limbed self bow with 10" stiff levers 68" TTT shoots those numbers too with a 10 grain arrow.
Seems a fat FDC is essential for extra speed.
I believe you, I have seen the same thing a number of times over the years. we call them outliers but they really are not, we just happened to get everything exactly right and don't always know exactly what we did right.
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Yes. Apart from stiff handles I can't imagine what else it would apply to.
I can't honestly tell a difference between an angled or a curved static tip if the tips end up in the same relative position and the portion is the same length.
It may register on a measured force draw but the feeling to the hand and arm would be hard to discern.
Pat, one of the big differences between a heavily reflexed r/d bow and a recurve is that a recurve can still maintain more static limb. Too much reflex in a r/d bow and you get a squishy limb with too much working limb. Most of the losses in a bow are through vibration, the more working limb we have the more vibration losses we have.
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I was referring more to the shape of the static tip. Say a 90 degree more or less angled tip versus one that is a half circle.
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Seems the more work a person can get out of a shorter working area while maintaining it's integrety there can go far for any type of bow really in efficiency.Getting the most out of it so to speak.With the outers reduced properly but stiff yet.Just one way to look at it I guess.A fine line to walk on that's for sure.It's a sorta complex question really why.There's many things to consider.The reason for the diverse answers on the subject.
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I think TBB basically said perry reflex, the mass thing principle and outer limbs as light as possible make more of a difference than recurve vs. straight?
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well I don't want to get in trouble here but I bujlt and sold glass bows for a while and did a lot of testing on all brands of bows. The best 'scientific' data out there for the masses are the tests Blacky did for the TBM. Everything tested the exact same, same specs, fingers and machines with fast flight strings and 9 gpp arrows. I'm an engineer so I really enjoyed reading these. I had a buddy who gave me his whole collection of TBM so I went through all of them and pulled out all the reports so I had a guideline on how my bows were performing. So that being said, the fastest bow he tested was a recurve that shot 193 with a machine. The only longbow that came close was Adcock's hybrid longbow. I love a straight limb longbow as much as any design but don't let the love of the lore affect reality. Its the least efficient bow design. In all my testing, I have never seen a hill style glass longbow shoot over 170 drawn to 28" and 9 gpp. I've tested some myself and also other hill type designs and the vast majority fall into the 160 range some in the 150s and this is glass let alone self bows. There is no doubt in my mind that a good self bow craftsman could build a self bow that would compete with this but probably not most. From all my testing, a good rule of thumb that I noticed with bow designs was 160s for longbows, 170s for slight D/R longbows, 180s for hybrids and high 180s for recurves. Just my findings
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It's not just string angle. Considering long bows have good string angle. It's also about the length of the limbs. Greater length creates greater moment arms which increasr the inerta. The biomechanical equation for inertia is mk^2, where k is a variable of length and m is mass. As you can see length increases inertia much greater than mass does, since its variable is squared. The ability for the limbs to snap back in place as quickly as possible is expressed as angular velocity. Greater inertia causes angular velocity to drop. For example, in ice skating when they put their arms out they rotate more slowley than when they pull their arms in. In fact when they pull their arms in they spin much much faster. Notice the mass was not changed. The only thing different is how close that mass is to the axis of rotation. The sam principle applies to bows. Longer limbs are more stable and accurate. But for the same reason they can not rotate back to brace as quickly.
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But they do so with less leverage
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well I will just throw this in for fun,, last week I shot a straight tip sinew back bow I have been working on,,
55 1/2 nock to nock
55#@ 26 inches
180fps with 500 grain arrow,, about 9gpp
8 strand fast flight
big feathers on the arrow
most of the shots were in high 170's
I feel like a good release accounted for the 180 fps,,
I didnt have anyone spotting for me, I had tape on the arrow at 26 inches
I weighed the bow with a hand scale.proably not the most accurate,,
I am just saying these figures are a rough estiamate,, but a good indicator of what a straight tip bow can do,,
i have found in my experience, that a good release and fast flight string are a big part of improved arrow speed,,
I think I was building bows that shot really well, but never appreciated it with a heavy b 50 string and no so good release,,but alot of shooting though the chrono has improved my release and the lighteer string adds fps to that,
maybe this bow would have shot faster with a longer draw,, but since the sinew came off as posted earlier,, I wont ever know,,:) :NN
I hope to experiement with some recurves in the future,,and appreciate all the input,, (-S
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Well to insure my figures were right us fellas go to a 3D shoot a few times a year here too.At that shoot a chronograph is set along the way to the targets.Costs a dollar a shot.I got exactly the same readings shooting through that chronograph as mine.Surprised the FG bows long ago with that but not anymore because they shot through there too with their FG bows and saw them not shooting any better on a lot of them.It was an educational experience to say the least.
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But they do so with less leverage
Hence recurves. Its the best of both worlds. You get the leverage and good string angle of a longer bow from the recurves/"levers" but also shorter limbs so they can rotate quicker when they snap back to brace.
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Brad, very impressive. Jawge
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thanks Jawge, I just got lucky on that piece of wood,, but have always felt the straigt tip bow was underated,,, this discussion has brought to light alot of interesting views, and I am less confused at this point,, and feel that the recurves can be faster,, but not as much as some had indicated in the past,, I think some of the conclusions have been very realistic,, (-S
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This is a very interesting topic hope it keeps going but common sense tells me at a Certain length there is probably diminishing return recurving and if you have a strait limb bow at the lightest durable mass and recurve it & takes additional set it probably is going to be a slower bow then if just left strait but there is so many dynamics at play on this topic ,length,self bow, sinew, composite,bendy vs handled bow, etc it's hard to compare apples to apples
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But they do so with less leverage
Hence recurves. Its the best of both worlds. You get the leverage and good string angle of a longer bow from the recurves/"levers" but also shorter limbs so they can rotate quicker when they snap back to brace.
I've been considering that since i typed my reply. I have almost run out of arguments for my initial view point and am leaning towards recurves having an advantage.
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This thread puts me in the mood to build a recurve. (-P )W( :BB (SH) :G
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Sleek I like it that you can outthink your self,, very postivie, :BB
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Just putting puzzle pieces together. I may not have all of the pieces, but with enough, i can rekcon what the rest are.
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WARNING. THIS POST MAY CONTAIN TRACES OF NUTS
If you get leverage and reduced string angles from recjrves, I can assume only they are because of each other. Leverage is a function of string angle.
If I take this and run with it, then the lower the string angle the more leverage I have. This creates in my mind a recurve that at full draw never has the string leave it. My mind instantly compares two recurves, one with large radius, the other small. The string angle stays the same no mater the radius as the bow is drawn. So now my mind favors small sharp hooks for weight reduction.
To carry this though further, my mind visualizes a recurve fashioned so the string just begines to come off the end of the recurve once full draw is hit. Any more wood in the recurve beyond where the string just comes off is waisted weight.
I now compare bow lengths. To keep the string on a short bows recurves you may need hooks that are 90 degrees. But if you lengthen the bow a certain amount, you could get away with 30 degree hooks and still keep the string on the recurves to that last inch of draw. That allows you to take advantage of the longer bows advantage of having a naturally lower string angle even without recurves.
I imagine in my mind a small recurve the radius of a golf ball vs one the radius of a bowling ball. The amount of string that comes into draw as the bow is drawn is much less on the golf ball sized recurve, forcing tje limb into more bending and stress. The bowling ball recurve lets off more string as the bow is drawn stressing the limb less because less bend is needed to reach full draw because more string is coming into the draw. To allow myself to elaborate and be more clear, its a distance/circumference thing. The larger the radius the longer the string is that sits on it etc...
What advantages could be had with either situation? Well, the larger recurve is less stressed so the limbs can be mkre narrow to allow less limb mass. Also, the bending could be more focused towards the fades allowing for less bending limb and less vibration losses. The tighter radius would require a longer working section of limb to handle the fact that it is more stressed. This would allow it to have more losses due to vibration. However tip mass does come into play as well with the obvious benefits.
I draw the conclusion now that a shorter bow with larger diameter recurves is the best bet. Seems the best of all worlds. Large radius recurves reduce how much beding is needed, keep the recurves narrow enough to reduce weight and remain stable. The shorter limbs will be less stressed and have less vibration, allowing for thicker wider limbs to fo the work. Ideally, if a bow could be so designed, it would bend only out the fade then go straight to large static recurves. Keeping in mind as well, we want to keep the effective length of the bow as short as possible to take advantage of the fact objects spin faster in tight arcs such as the arc formed as the tips come around to full draw.
Of course, i reserve the right to be wrong.
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WARNING. THIS POST MAY CONTAIN TRACES OF NUTS
If you get leverage and reduced string angles from recjrves, I can assume only they are because of each other. Leverage is a function of string angle.
If I take this and run with it, then the lower the string angle the more leverage I have. This creates in my mind a recurve that at full draw never has the string leave it. My mind instantly compares two recurves, one with large radius, the other small. The string angle stays the same no mater the radius as the bow is drawn. So now my mind favors small sharp hooks for weight reduction.
To carry this though further, my mind visualizes a recurve fashioned so the string just begines to come off the end of the recurve once full draw is hit. Any more wood in the recurve beyond where the string just comes off is waisted weight.
I now compare bow lengths. To keep the string on a short bows recurves you may need hooks that are 90 degrees. But if you lengthen the bow a certain amount, you could get away with 30 degree hooks and still keep the string on the recurves to that last inch of draw. That allows you to take advantage of the longer bows advantage of having a naturally lower string angle even without recurves.
I imagine in my mind a small recurve the radius of a golf ball vs one the radius of a bowling ball. The amount of string that comes into draw as the bow is drawn is much less on the golf ball sized recurve, forcing tje limb into more bending and stress. The bowling ball recurve lets off more string as the bow is drawn stressing the limb less because less bend is needed to reach full draw because more string is coming into the draw. To allow myself to elaborate and be more clear, its a distance/circumference thing. The larger the radius the longer the string is that sits on it etc...
What advantages could be had with either situation? Well, the larger recurve is less stressed so the limbs can be mkre narrow to allow less limb mass. Also, the bending could be more focused towards the fades allowing for less bending limb and less vibration losses. The tighter radius would require a longer working section of limb to handle the fact that it is more stressed. This would allow it to have more losses due to vibration. However tip mass does come into play as well with the obvious benefits.
I draw the conclusion now that a shorter bow with larger diameter recurves is the best bet. Seems the best of all worlds. Large radius recurves reduce how much beding is needed, keep the recurves narrow enough to reduce weight and remain stable. The shorter limbs will be less stressed and have less vibration, allowing for thicker wider limbs to fo the work. Ideally, if a bow could be so designed, it would bend only out the fade then go straight to large static recurves. Keeping in mind as well, we want to keep the effective length of the bow as short as possible to take advantage of the fact objects spin faster in tight arcs such as the arc formed as the tips come around to full draw.
Of course, i reserve the right to be wrong.
Could be you think too much :OK
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How else am I supposed to do anything that mimics intelligence?
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a strait tip bow so relaxing,, (SH)
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Sleek, I htink you have a pretty decent concept except for one thing. A bow with big recurves reduces leverage at brace so it pulls harder. As it starts to lift off it gradually starts returning leverage and at the end still maintains lower string angles which increases leverage. This basicaly gives you a smaller difference between starting pull weight and final pull weight. Adding up to more stored energy. So take away leverage at the begaining and slowly give it back.
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Would that mean there is a better shape for a recurve other than round to take full advantage of that concept? An elliptical shape recurve for example? Or more like, one that gets a tighter radius closer to the tip, visualize an elf shoe tip. The curve starts off large and tightens up as it goes... curly cue
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you guys are hurting my head,, but in a good way :BB
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If there is an optimum shape of the recurves themselves then I have never found it. I have tried large curves and small ones and found that there is no difference in performance between the 2; in fact I would suspect that the small curves would be better for flight shooting due to their lighter mass. The one major difference I have found is that smaller recurves are less prone to introducing twist in the limb
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Sleek....you just basically spelled out how a compound bow works 8)
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Sleek....you just basically spelled out how a compound bow works 8)
Well, that does it, I quit.
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If there is an optimum shape of the recurves themselves then I have never found it. I have tried large curves and small ones and found that there is no difference in performance between the 2; in fact I would suspect that the small curves would be better for flight shooting due to their lighter mass. The one major difference I have found is that smaller recurves are less prone to introducing twist in the limb
That is exactly what I have found Mark. The bigger round curves do have more capacity for energy storage but they loose out in efficiency and being stable. I don't know the best angle I would expect that anything that lifted off at a very even rate would be desirable. A big static recurve has to bend too much in the inner limb to get the curves to open up.
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this have been a great thread, and narrowed down alot of experimentation for me on my next recurve,,just gonna try and keep it simple with smaller recurves,, and see what I can do,, :)
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No data to back this up ,but a trimmed out recurved mollegebet lever shoots quite well