i'am agree with you.

 

Works pretty close “for me”. According to the math it’s 27 5/8” and in reality I’m just under 28” with a moderate weight recurve (#48). Back when I shot an 80+ pound ASL longbow which I could draw and hold at anchor was a little over 26”. The shooting style and what I call body compression resulted in the shorter draw. Currently shooting an Oneida compound bow with fingers and with the let off I’m holding 25 on the fingers. I have that set up for a 29” draw which has me stretching back just a little and I like it, had tried shorter modules but felt cramped.
So while actual draw can vary because of bows and different techniques I do feel wingspan gets you in the ballpark.

 

I don't think the calculation has taken wedge alignment geometry into account.

 

That method shows 28 inches for me. That is my draw length with compound and release. I draw 29 with traditional once I found alignment.

 

Good thing sbout trad is we really don't need to know the actual number to get started right. Have someone standing behind spot alignment. After form has developed, just mark an arrow at the back of the bow.

 

I dont think trying to determine just how accurate it is , is useful.
Maybe its close on 30% of people maybe its close on 60% of people.

Its better than nothing, but it shouldnt be relied on for anyone.

And it never seems to work for people with wide shoulders.

 

I used to use the wing span method initially then determine my actual by measuring at full draw with 1.75 from grip throat.

In doing this when shooting I tried to ensure I came back to that distance with my anchor. By doing that others would tell me that I need to draw further to get in the proper alignment, including Bob Wesley who was an archery coach for longbows and trad shooting. He told me with the strength in my shoulder I could get away with it.

I then started training with the Formaster for strength and it enabled me to draw with my shoulder and back muscles. It showed me where I should be to get proper back tension. When coming to the proper draw for me it was easier to draw and hold. My draw is now 30" which feels so much better and stronger than 28.8".

When I shot longbows at the time I was overbowed most of the time and my draw wound up at 28".

I wish I knew more about alignment, drawing with my shoulder and back muscles, and shooting lighter bows 55 years ago. It would have been a much more pleasant and productive journey along the way.

 

Honestly, well for compound shooters it matters for setting the back wall up (and even then it's 'draw length with x brand/style release), with traditional it doesn't really matter. The only time it really matters is for the people with the longer draws when doing arrow selection, for which an approximate is good enough. Otherwise? Spine is based on draw weight range at a certain arrow length and then fine tuned with tip weights and trimming the shaft. It's even less important with ILF bows and their draw weight adjustment bows.
We, as archers, tend to get fascinated by the minutiae, look at all the threads on FOC.

 

Most of the archery shop around here at that time had a kids bow with a arrow mark in inches and you drew it with whatever you used to draw. They call that your actual Drawlength. You set your bow up to that. AMO was for arrow tuning a selection. Just a standard recommendation for strings, bowlength, drawlenght, arrow lenght. There is a different approach to measuring your actual Drawlength with a yard stick ruler. I use the Renpho smart tape measure, like i did in my precise EPE Testing. It shows i am at 27.95" vs 71÷2.5=28.4 wingspan method.
Hope this helps.
DDD

 

It would be interesting to do an experiment and see how much variance we get. It would have to be done under controlled conditions, i.e. standard method of measuring draw length and wing span.

This is the type of thing I could do at one of our archery club sessions since I could control the variables.

While interesting, I am not ready to do this. I am not shooting at the moment since I took a fall on a mountain on December 2 and cannot shoot yet.

I have started hiking but I cannot pull from my ribs.

 

It would be interesting to do an experiment and see how much variance we get. It would have to be done under controlled conditions, i.e. standard method of measuring draw length and wing span.

This is the type of thing I could do at one of our archery club sessions since I could control the variables.

While interesting, I am not ready to do this. I am not shooting at the moment since I took a fall on a mountain on December 2 and cannot shoot yet.

I have started hiking but I cannot pull from my ribs.

Sorry to hear about your fall Hank. I fractured four ribs during a steep descent on a mountain last year, bow in hand. It affected just about everything, including breathing and sleeping. Thankfully I was back to shooting my lowest poundage bow within some weeks. Anything heavier was impossible. Wishing you a fast recovery!

And a great idea for wingspan disparity statistics gathering by the way.

 

I never could rely on wingspan metod either. My wingspan is 70-3/8" divided by 2.5 is 28.15" but my measured AMO draw length is 25-5/8". I am 5'-6", not sure why there is such a large difference, on average, one's wing span and height are very close, mine is a differnce of 4-3/8" This an ape index of 1.06.

 

Interesting. I think that's the biggest difference I've heard of. Also, looking back every DL I've seen that differs a lot from the wingspan calculation has been longer, not shorter. You and DDD are similar in this way. Goes to show there's no one rule. A DL is what it is!

 

New DL Formula = Old DL Formula x 1.04

 

cabin fever, guys?

 

Summer here, in the other hemisphere. The season with more newcomers to the sport asking what their draw length is.

 

Totally. I'm almost ready for a 'what is instinctive and how good can you get with it?' argument thread.

 

for me, I don't understand why anyone would want to GUESS at draw length - when it is something SO EASY to MEASURE.
all it takes is equipment ANYONE SHOOTING BOWS already has...bow, and tape measure...and an arrow, and a Sharpie. Maybe add in a piece of cardboard 3 inch square with center hole to slide on arrow.

 

It is a method for mail order of equipment for beginners. Traditional Archery is predominantly a mail order industry. Your local archery shop makes its money with compounds.
If you have someone on the phone and they have a tape measure, they can easily measure their wingspan by themselves in a few seconds.
How this measurement is then used, depends on the experience of the salesman on the phone.
If you want to recommend a bow length to someone on the other end of the country and you have his wingspan, you'll make sure that the bow will not stack or is terribly too long.
If the wingspan is terribly long, some of the production bows will be out of the question, because they are really optimized for 28" draw length.
Example: Wing recurves are perfect for 28", 29" being about the max. before they stack. I assume some Bear models are like that,too.
Bowyers know the Force draw curves of their bows and can recommend a good bow length to novice customers. Especially important with ASL bows or straight longbows.

 

@tecum-tha raises the key point. Not all have luxury of a bow in hand when looking to sort a fitting bow out for someone, to get them started. No shops within miles, if even available. Or you are buying a set of arrows as a gift for a neice or nephew etc in another country. And so somewhere along the way, out comes the tape measure.

I am recently back from travel visiting extended family on a small island with no archery shop. Everything is mail order. With me I had a 45lb TD longbow and a 56lb ILF recurve. Two were very excited by the mere sight of them and expressed interest in trying. I could not have anticipated this. The 45lb was far too heavy to get a guage of DL.

And so out came the tape measure and that wingspan calculation. I'm buying a bow and arrow set for one, and gifting another.

 

Well, if you have a bow for them to grip even when it is too heavy. You just align them with the bow in one hand and their hand at their anchor point without an arrow and measure from anchor to back of bow. That will get you probably slightly longer, because there is no compression force on the bow arm. But it will get you closer than wingspan measurements.
Wingspan is good for self performance when there is nobody there with any knowledge.

 

For me it was easier to do the paper over the arrow shaft, then draw and measure method.

 

My left arm is about 2 inches shorter than the right so I think that throws my wingspan to real draw length off. Going to take 2 inches off a couple of 30" arrows to see how they fly. Already took an inch off 1 that got damaged and it still sticks out front enough when drawn to be cut shorter.