Trad Gang
Main Boards => PowWow => Topic started by: Blacky on January 26, 2012, 05:30:00 PM
-
Today I received a set of the brand new Dryad ACS ILF Recurve limbs, that will debut at the Kzoo show.
I did some testing today and here's the first results:
Dryad Legend ACS ILF Recurve Limbs on 15" Epic Riser
Draw Weight @ 28": 42,6 lbs
Stored Energy: 41,20 ft-lbs
Ratio SE/PDF: 0,97
Arrow Weight: 384 grains
Arrow Speed: 198 fps
Kinetic Energy: 33,44 ft-lbs
Efficiency: 81,1%
(http://www.blackyschwarz.com/pics/rec-sm.jpg)
-
Wow those limbs dont even start to climb even at 32"
Were the limbs bottomed out, that curve does not even get back to level until 30"
-
Remarkable performance!
My guess is that you may have tested merely one set-up that was faster.
Either way, this is elite performance.
-
The limb bolts were set in the medium position.
I just talked to John and he told me that the bolt-on version is faster than the ILF version. We'll see after the Kzoo show, when I'll receive mine.
Blacky
-
You may want to try turning them in and see what you get, i know you will get more speed due to increase in pounds at draw but(i in no way know what i am talking about and rely on what i read)i have read that you get the most out of a ILF limb if your draw length is at just before the curve starts to rise. You may get a jump in efficiency, not that there is any thing wrong with 81%
-
Rick,
I normally test all my ILF bows with the limb bolts in the medium position. :)
Blacky
-
I understand, got to have a set system when testing, just my curiosity poking at me.
-
I would expect the new Orion Design riser to be a little faster due to having significantly less deflex, thus a longer power stroke.
Click on the 'X'
(http://images.imagelinky.com/1327620723.pptx) (http://images.imagelinky.com/1327620723.pptx)
-
WOW that arrow is moving for less than 43#!
-
That is quite an accomplishment-1st ACS RC limbs to boot! Smoking hot! :thumbsup: :thumbsup:
-
Great performance for the weight and the middle adjustment
-
Yow great stats. Thanks Blacky
-
Pretty swift !
-
what is your brace height?
-
Blacky,
Have you tested their ACS 4G longbow limbs?
-
Those are pretty good numbers.
-
Ya some great performance numbers....Well done guys!
-
OK, I need an education on how to read/interpret the graph. And what’s considered good, fair and bad. Math and engineering have never been my strong point.
It seems to me that the limbs do not “stack” from 28” to 32” inches which I think is a very good thing. The poundage simply increases in a straight line. Simple enough?
At a 20” draw length the “straight” line draw is just a bit less than 24 lbs while the bow actually draws a bit over 31 lbs. Is that correct? Is that considered beneficial or good?
Is the fact (?) that you have a heavier draw in the lower poundage (than in a straight line) is that somehow good? Is that the price you pay to have no stack at the upper end?
Is the straight line a utopia that bowyers strive for?
Ok…thinking out of the box…
Is it possible to “reverse” the red line? If you hold the red line at each end and rotate it so it’s under the straight line…instead of pulling more than the straight line it actually pulls less until you reach the 28” draw length. If that is possible would that be considered good?
Seems the speed is very fast for a + - nine grains per lb. Is there a way to extrapolate what it would be at 10 grains per lb?
Like I said, I am not the sharpest tool in the shed when it comes to this stuff so I will appreciate your accurate feedback.
Thanks,
Bob
-
I shot them at the Kzoo expo tonight. Very fast!! The shot distance is short, but you can still tell the bow is quick and hitting very hard. This year they have Rinehart targets and the arrows were hard to get back out of the target. I shot about 20 tope end bows about the same weight and the new ACS recurve was the hardest hitting. Not quiet with bare string. I would like to shoot one again with silencers to see how it quiets down.
I also shot their standard static tip limbs and loved those. Longbow quiet with nothing on the string.
-
Blacky
are the bolt-on versions is faster than the ILF version? just wanted to see if you had the chance to compare yet. thanks!!!
-
I shot the recurve limbs at K-ZOO also very fast, but they were noisy without any wool silencers. I spoke with John and he told me that the acs recurve limbs would pick up a good 5 fps with the bolt down limbs on the dryad bolt down riser over the ilf riser
-
tracker1 is right - the bolt down limbs are optimized on the bolt down riser, and optimum is very difficult if not impossible to achieve when working with a compromise system such as ILF. ILF is fantastic because it allows so much interchangeability. But the benefit of that interchangeability comes at a bit of a cost when talking about optimized performance.
-
and what about their lateral stability?...a french archer has measured in centimeters the lateral torsional stability (rigidité latérale des branches) of a bunch of limbs....all of them aren't equal by far...so It would be a great improvment if one can compare them with these new ACS limbs.
(http://img823.imageshack.us/img823/6291/rigiditeq.jpg) (http://imageshack.us/photo/my-images/823/rigiditeq.jpg/)
-
good info but your pic is too big and will be deleted soon.
-
reduced, I apologize !
if not, any idea about their lateral stability?
-
What Draw weight were those limbs? This is the most important point, since you can only compare limbs of the same length and draw weight.
Blacky
-
Originally posted by Blacky:
What Draw weight were those limbs? This is the most important point, since you can only compare limbs of the same length and draw weight.
Blacky
according to the author the most important difference was 1/2# between the limbs making 46@28 for a 68" AMO bow.
-
up!
-
Foudarme, you're out of luck. My limbs are 40@28" on a 19" riser plus they are X-Long, so no comparison possible from my side.
Blacky
-
If I read the original post correctly, the speed of the ACS Recurve limbs was 198FPS. @nine GPP with a release! Correct? Then if I remember a Bow test in TBM , there was a recurve with glass limbs ( Name unmentioned because they are not a sponsor here) that shot the exact same speed. ???? :dunno:
-
Great results, and draw force curve is very nice for long draws: that's nice!
Blacky, if i remember well, the Dryad Orion with standard glass limbs was tested @ 195 FPS for 9 gpp no?
-
One thing you want to be aware of is trying to compare bolt-down bows to ILF bows. Blacky will be testing the Orion bolt-down with the new limb in the near future and it will out do the ILF by a good margin.
If my memory serves the test on the old Orion with the recurve in TBM was 195.
Mike
-
Originally posted by Blacky:
Foudarme, you're out of luck. My limbs are 40@28" on a 19" riser plus they are X-Long, so no comparison possible from my side.
Blacky
thanks, blacky
mayby JH could talk about it, he must to know a lot about their torsional stability?
-
foudarme,
I do not have a fixture that enables me to objectively measure how torsionally stable these limbs are. Perhaps I will one of these days but I currently do not have one. However, subjectively I can say that the Generation II ACS recurve limbs we're now building are more torsionally stable than any other limb I have ever tried to twist by hand, and I've tried to twist quite a few. I think that Mike and Jason would agree with that rather broad statement.
Subjective observations like the one I just made above are not my style. I prefer to limit myself to objectively-measurable and objectively-comparable information. Without a data base of limbs that are the same length and the same draw weight for comparison it's impossible for me to be anything other than subjective.
I will say this - we just built a set of 31# @ 28" XL ACS recurve limbs and it was impossible to twist them by hand, no matter how hard we tried. A very light-weight set of limbs in an XL length should be as torsionally unstable as any set of limbs a bowyer can build. Anyone holding or using this particular set of limbs would be surprised by how torsionally stable they were. The Crazy John's carbon really does the trick for stability.
-
Originally posted by John Havard:
foudarme,
I do not have a fixture that enables me to objectively measure how torsionally stable these limbs are. Perhaps I will one of these days but I currently do not have one. However, subjectively I can say that the Generation II ACS recurve limbs we're now building are more torsionally stable than any other limb I have ever tried to twist by hand, and I've tried to twist quite a few. I think that Mike and Jason would agree with that rather broad statement.
Subjective observations like the one I just made above are not my style. I prefer to limit myself to objectively-measurable and objectively-comparable information. Without a data base of limbs that are the same length and the same draw weight for comparison it's impossible for me to be anything other than subjective.
I will say this - we just built a set of 31# @ 28" XL ACS recurve limbs and it was impossible to twist them by hand, no matter how hard we tried. A very light-weight set of limbs in an XL length should be as torsionally unstable as any set of limbs a bowyer can build. Anyone holding or using this particular set of limbs would be surprised by how torsionally stable they were. The Crazy John's carbon really does the trick for stability.
john...the fact that you can't twist some so light limbs by hand is obviously a very good sign..I have at home some F7 40# long limbs that I can twist by hand...to the opposite I have some 45# border long hex v limbs that I can't...but as you say hand twisting has nothing of scientific. If you need any idea for making a rigidity bench tester you can easily find some examples on internet forum such as integralsport in France or archery interchange in UK.
jean
-
Merci' Jean. I will check that out.