Dryad ILF ACS Recurve Limbs: First Results

[tracker1]

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

[John Havard]

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.

[foudarme]

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.

   

[wingnut]

good info but your pic is too big and will be deleted soon.

[foudarme]

reduced, I apologize !

if not, any idea about their lateral stability?

[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

[foudarme]

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.

[foudarme]

up!

[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

[SERGIO VENNERI]

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. ????  

[hybridbow hunter]

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?

[wingnut]

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

[foudarme]

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?

[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.

[foudarme]

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

[John Havard]

Merci' Jean.   I will check that out.