Why no fibreglass lever bows?

[mmattockx]

https://www.youtube.com/watch?v=m5ZUD8PyKAU&list=WL&index=5&t=4s

Why is it there are not a lot more of this design of FG bow? It is essentially a FG version of a traditional horn/sinew bow and it seems to me that FG is very well suited to this design, allowing a very concentrated bending area on the limb and while the lever minimizes the weight at the tip that is the weakness of FG.

Thoughts? Experiences with making this style of bow?


Thanks,
Mark

[B-JS]

I highly doubt, that the lever is lighter than a Standard Limb.
This May give a Smooth Draw with nice energy storage.
But i Bet IT will have SERIOUS  handshock.

[Mad Max]

I made some
When I get back to the house I will post pictures

[Mad Max]

Not the same.
Made these back in 2014 or so.

could have been a good bit thinner


7" lever

[mmattockx]

7" lever

Very nice, that's the style I was wondering about. Any pics of braced and full draw? How did this one shoot?


Mark

[mmattockx]

I highly doubt, that the lever is lighter than a Standard Limb.
This May give a Smooth Draw with nice energy storage.
But i Bet IT will have SERIOUS  handshock.

You would be surprised how much lighter the lever is than a conventional limb. FG is heavy compared to wood (over twice the weight of most core woods) and limb stiffness goes as the cube of the thickness compared to linearly with width so a narrow, thick lever is significantly lighter for any given level of stiffness.

Levers are used regularly on flight bows where efficiency is paramount and they certainly don't have handshock problems.


Mark

[Flem]

I am wondering why all the speed freaks are not making this style, if it's so superior?

[Mad Max]

I don't have any more pictures.

Flem
"A well-made 60 pound Manchu bow of all traditional materials will not outperform a well-made 60 pound English longbow. The Yongzheng emperor stated that from 80 pounds and up is enough for the military, so when Wen Chieh offered to make a bow for me I ordered that poundage. It was only when we tested this bow that the facts and figures started to impress again. At 82 pounds its draw weight started to outperform the disadvantage of the weight of its ears, results were impressive. The 82# Manchu bow, made by Wen Chieh, outperformed a well-made 128# yew longbow, shooting the same 1230 grains (80g) military weight arrow a stunning 190fps against 170fps for the longbow. This is exactly the reason why the Manchu bow used to have a bad reputation: People were testing low draw-weights that were too low and found no significant advantage in poundage pulled versus arrow velocity to justify its complex construction. The design really is made for war and hunting, to do damage with heavy arrows. They may not be the fastest bow, but no other bow design can launch an arrow that heavy, that fast. "

[Flem]

Sorry if I'm dense, but I am missing the connection? The guy in the video is building low draw weight, high FPS bows. Not sure how to classify his bows. Unlike the Manchu bow, he designed the speedbow  to outperform other designs at low poundage.

[mmattockx]

I am wondering why all the speed freaks are not making this style, if it's so superior?

This is why I am asking. I want to know what I am missing or if it is all BS. As I mentioned, there are lots of primitive class flight bows that use levers and perform very well with light flight arrows.


Mark

[B-JS]

Even If IT would maybe outperform a Standard Limb....
So there is a Lot of Stress in a very small area of the limb.
So it won't have a Long Life.

[Shredd]

  I was bought up on the adage, "Believe nothing you hear and only half of what you see"...  Until a bow is tested by an independent tester and on a shooting machine, I take most things with a grain of salt...

  That's why I took the time and effort to get my bow tested by Tradlab... I am perfectly capable of accurately testing my own bows but an independent test is putting your money where your mouth is...

   I believe in the video he is testing at 9gpp and makes no mention of draw length, he is pulling behind his ear and is snap shooting...  All when combined can buy you another 30 to 35fps or more plus the fact the arrow in under 10gpp, which you must take into account...

   I like the design of Mark's bow in the top pics...  My fastest design is very similar with less hook angle... You see how he has a consistent bend all the way to the base of the hook...  I find that consistent bend through most of the limb to be very important when it comes to speed... At least in my designs...  When I designed my bow I took what I thought was the best from 3 bow designs...  The slenderness of the LB, a tight hook of the recurve and a small flat section of the lever bow...

   Do you want to see some badass lever bows??   --Saluki Bows--
 I talked to this guy on the phone...  Real nice guy...  He only lives about 2 hours away from me and said it was ok that I come to visit with him and talk bow talk...  But then Covid came...  Maybe I will hit him up this winter...  I believe he said his personal favorite bow was the Turkish one...  I plan on taking my ratchet tree and chronograph and see if he is into me doing some dfc's and speed testing on his bows...

https://salukibow.com/

[Flem]

This is from the Opa's website. I am asking you guy's that are into speed and design if this is legit?
I'm thinking 175fps is zippy for a #35 bow and hunting weight arrow

"Calculating Arrow Speed from Opa Bows
Calculating The Speed Of Hunting Arrows Shot From Opa Bows

Without The Use Of A Chronograph

Written By Peter Laffin

Most bows’ speed will change approximately 1fps with each arrow weight change of 3 grains – 4 grains. For example, if one increased the arrow weight by 30 – 40 gains it would slow the arrow velocity down 10fps. Inversely if one decreased the arrow weight 30 -40 grains it would speed up the arrow velocity by 10fps.

Opa Bows’ speed will change approximately 1 fps with each arrow weight change of 5 – 5.5 grains (this is due to the higher efficiency of Opa Bows). For example, if one increased the arrow weight by 50 – 55 grains it would slow the arrow velocity down 10fps. Inversely if one decreased the arrow weight 50 – 55 gains it would speed up the arrow velocity by 10fps.

Using the ASR on an Opa Bow one can calculate the approximate velocity for any arrow weight. For example, Opa’s personal hunting bow has a draw weight of 35# @ 28”. It’s ASR is 195fps for a 9gpp arrow (35# draw weight x 9 grains per pound = a 315 grain arrow) and it shoots a 500 grain arrow at 165fps. Opa’s hunting arrow weighs 415 grains. That is 100 grains more than the 315 grain arrow that travels 195fps. Divide 100 grains by 5 grains and you get a change of 20fps (100/5=20). Opa’s hunting arrow is traveling 20fps slower than the 315 grain arrow. 195 – 20 = 175fps (this actually checks out with the chronograph).

Opa’s hunting arrow specs:

Arrow Shaft Gold Tip Entrada 500 spine

Arrow Weight 415 grains

Arrow Speed 175fps

Arrow weight/pound draw weight 11.8gpp

Arrow FOC 19.2%

Arrow Kinetic Energy 28.19 ft lbs

Arrow Momentum .322
"

[Mad Max]

There are a lot of glass lever bows out there.
Here is one.
They bend coming out of the fades and levers come way back so  a 50" can still be drawn to 28/30"

[Flem]

So he is reinventing the wheel, or recurve in this case. Maybe a little longer and a bit flatter, single curve.

[Black Mockingbird]

Even If IT would maybe outperform a Standard Limb....
So there is a Lot of Stress in a very small area of the limb.
So it won't have a Long Life.

Not true at all...

You simply make your working limbs wider than a "standard/normal"bow. Which in turn makes your working limbs thinner being able to safely bend more than a regular narrower thicker working limb. Take a piece of paper for example and see how far you can roll it up and bend it before it creases...then take the same piece of paper and fold it into quarters or more and see how far it bends before creasing up.

And a well made lever bow shoots with zero shock and very smooth to your previous comment as well...both of your comments are chaff in the wheat.

[Mark R]

I know a few people who shoot these style of bows, some pretty much buy them cheaply made in China and not sure weather or not there made well, alot are not, I'm sure some are, I have seen them myself  blow up and heard from people who have them say they break down more than others, could be many reasons why who knows, I've heard good things about Saluki Bows and the wait time and price are similar to most quality custom bows. True Horn Bows are a work of art but must be maintained and used with more care than most others. Not to sure about the video on the new glass horse style bow that squeaks when you get to full draw, scary. You would think it would have been tested before sending out to be evaluated.