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Discussion Starter · #1 · (Edited)
I see a major confusion here, that can really play up when buying trad bows and helping folk out, esp sharing tuning tips and tricks: there are different ways to measure draw length and we don't communicate which method we use when we say "My draw length is..".

I was raised on the wingspan method, of measuring arm span and divide by 2.5. Later it became from nock throat to grip throat, the 'natural' DL we knew it as. They tend to be about the same. Easy as.

Over the years buying single piece and TD wood bows (Bodnik, Bear, Black Hunter to name a few) my 28.7" 'natural' or 'true' DL works out at the draw just as expected. You give that number to the bowyer, bowyer adds depth at grip. What the doctor ordered.

Then came the popular nock throat to back of bow method, which can vary a lot from bow to bow. On one of my thin stickbows my DL using this method is about 29.6"

But with ILF kit, it's another story, and the AMO DL (natural/true DL + 1.75") is what the bow scale is seeing. I'm well over 30" DL using the AMO spec.

By example I've a pair of new Sanlida X10s (cross carbon foam Oly) here marked at 38lb on a 25" riser. On a 19" riser I draw 48-49lb, not the 44-45lb I'd expect. My new Buck Trail (3k carbon bamboo) marked at 45lb on a 19" draw about 50lb on a 19" riser. That's AMO DL, felt on the fingers.

Which DL do you cite here on TT, at the shop and at the range? Grip throat to nock DL, AMO DL, nock throat to back of your goto bow DL, the ol' wingspan/2.5 DL?

EDIT: changed title and text for clarity, gave examples
 

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I have always known it to be throat of the nock to back of the riser or front of the shelf. It usually is very close to that even from bow to bow I typically measure 27.5". I learned quickly that the ilf world can be very tough matching limbs to risers with a certain expectation of exact draw weight. That was was primary reason for buying hoyt limbs for my hoyt riser. I pretty much knew what I was getting plus I had the shop scale them before shipping to be sure. It's important for me. I don't want a 42#bow scaling 45#. Some guys can shoot a range of weight very well. I don't want over 42#.
 

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... use the index card method to abtain your exact draw length to your anchor...
 
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Discussion Starter · #4 · (Edited)
... use the index card method to abtain your exact draw length to your anchor...
For my 'natural' or 'true' DL, I use a marked arrow and film myself pull it to full draw, lining up to grip throat, or have a friend or my better half mark the arrow lined up with the grip throat at full draw.

I then give that to the bowyer, who will add a number related to the bow thickness at grip.

But that's not the issue here, it's that some folk are citing their AMO DL, others their DL using the wingspan or another method. Bob Lee has his own method, and you read a lot of folk measuring to the back of which ever bow is in their hand, regardless of some bows having very different riser depths. ILF seems very much AMO based, your local stick bowyer not.

Bit of a mess I reckon. Makes shoe sizing look like a walk in the park!
 

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Two points.

1 Talking about the "wingspan" method just needlessly makes this confusing. What that approximates varies greatly from person to person.

2 The distance from the throat of the nock to the throat of the grip is not your "natural draw length."
Its a not a thing at all other than part of the calculation used to figure your draw length.

"Natural draw length" just refers to the draw length you would use on a light bow using good form.


You should of course verify with a bow makers what exactly he means by "draw length" but it usually mean amo although some guys base it on the front of the riser.
 

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Discussion Starter · #7 ·
Two points.

1 Talking about the "wingspan" method just needlessly makes this confusing. What that approximates varies greatly from person to person.

2 The distance from the throat of the nock to the throat of the grip is not your "natural draw length."
Its a not a thing at all other than part of the calculation used to figure your draw length.

"Natural draw length" just refers to the draw length you would use on a light bow using good form.


You should of course verify with a bow makers what exactly he means by "draw length" but it usually mean amo although some guys base it on the front of the riser.
I agree as to point 1. Still, the wingspan method is broadly used with newcomers. I suspect many new archers, some visiting this forum, walk around with that measure in their head.

Not sure about your 2nd point. Very often this is cited as the 'natural' or even 'true' draw length and used to determine bow fit (on its own, by the bowyer), and/or to calculate AMO length.

Example

"First, measure the distance between the grip’s pivot point (farthest part of the grip) to the nock point (where the back of the arrow rests). This length is typically called “true draw length”."
- How To Measure Your Bow Draw Length - ArcheryMind

Many times I've seen someone with a stick or tape measure measure someone's "true" DL this way, in a shop or at a range in Germany or France. They don't measure to the back of any random bow as bow risers differ in design. That number is then carried around in that person's head as their 'draw length'.
 

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Thats "true draw length" not "natural draw length"(even according to your link) but you will note that pretty much every reference you find to "true length" only uses it as step to calculate your draw length(whether it be AMO, Natural, bowyer specfic or etc.) as I said. Its a not a number normally used as a thing unto itself.
I agree as to point 1. Still, the wingspan method is broadly used with newcomers. I suspect many new archers, some visiting this forum, walk around with that measure in their head.

Not sure about your 2nd point. Very often this is cited as the 'natural' or even 'true' draw length and used to determine bow fit (on its own, by the bowyer), and/or to calculate AMO length.

Example



- How To Measure Your Bow Draw Length - ArcheryMind

Many times I've seen someone with a stick or tape measure measure someone's "true" DL this way, in a shop or at a range in Germany or France. They don't measure to the back of any random bow as bow risers differ in design. That number is then carried around in that person's head as their 'draw length'.
 

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Discussion Starter · #9 ·
Thats "true draw length" not "natural draw length"(even according to your link) but you will note that pretty much every reference you find to "true length" only uses it as step to calculate your draw length(whether it be AMO, Natural, bowyer specfic or etc.) as I said. Its a not a number normally used as a thing unto itself.
We agree not 'normally'. That was an English link, not representative globally.

But the fact remains, across different places and cultures we have the problem of no one globally adopted standard for measuring draw length in Western archery. Folk here on TT come from all over, and what you know is 'normal' may not be for others.

Archers cite their DL without citing the method, making it hard to help them. Some bowyers (many) ask for Draw Length without citing the method (Bob Lee cites and gives their own method). The 3 Rivers Dynamic Spine calculator uses the highly erroneous 'back of bow' method, which is esp tough when you're asked for a DL for a bow you don't have.

"The length you pull your bow back to anchor. Varies from shooter to shooter, and can vary from factory draw length. Can determine by drawing back an arrow and having someone mark the arrow on the outside of the bow when at anchor. Measure arrow from valley of nock to the mark."
If it was my dictatorship, it'd be AMO DL all the way.
 

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Wait - if you are asking about Asian archery or something say so.
They do a lot of stuff different - more than I know.

But you asking in English on an English speaking traditional archer sight.

Simply using the measurement from throat to throat as a draw length - is not a thing. Its not an accepted convention.

You said their was a "major confusion" when you you should have been saying "Im confused please explain this."
Which is fine - but dont double down on your own misunderstanding when its explained.
 

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Discussion Starter · #11 ·
Bob Lee has a bloody good point. The distance we draw a bow is almost certainly not representative of the length of draw at the actual point of release. Most archers draw further than they settle at aim. Hence measuring DL just by drawing a bow gives a false reading as regards bow performance and archer's state while shooting:

 

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Discussion Starter · #12 ·
Wait - if you are asking about Asian archery or something say so.
They do a lot of stuff different - more than I know.

But you asking in English on an English speaking traditional archer sight.

Simply using the measurement from throat to throat as a draw length - is not a thing. Its not an accepted convention.

You said their was a "major confusion" when you you should have been saying "Im confused please explain this."
Which is fine - but dont double down on your own misunderstanding when its explained.
Nope, seems you misunderstood the point of this thread. You can catch up or do something else.
 

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This thread is really confusing lol...

If you take the throat to throat measurement and add 1.75 or mark it to the front of the riser (or back of bow in trad terms), the measurement will be relatively close. Not enough to cause the weight variance you cite in your OP.

I'd guess that particular issue has more to do with riser geometry and possibly Sanlida being scaled at 26" as I believe I have read that before? I know I've read they generally come in much heavier than the expected weight. But that is not first hand experience
 

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This thread is really confusing lol...

If you take the throat to throat measurement and add 1.75 or mark it to the front of the riser (or back of bow in trad terms), the measurement will be relatively close. Not enough to cause the weight variance you cite in your OP.

I'd guess that particular issue has more to do with riser geometry and possibly Sanlida being scaled at 26" as I believe I have read that before? I know I've read they generally come in much heavier than the expected weight. But that is not first hand experience
You are correct the different between AMO draw length and draw length to the back of the bow is small on the majority of bows. It mostly matters to people who want arrows cut as short as possible or who have long draw lengths and cant find long enough arrows.

But he is talking about the distance measured from the grip throat for some reason - which is by definition 1.75" different.
If that was a convention commonly used it would be a problem I guess - but it isnt. So the whole thread is much adieu about nothing.
 

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You are correct the different between AMO draw length and draw length to the back of the bow is small on the majority of bows.

But he is talking about the distance measured from the grip throat for some reason - which is by definition 1.75" different.
If that was conevtion commonly used it would be a problem I guess - but it isnt. So the whole thread is much adieu about nothing.
Yes we’re basically on the same page.
 

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Discussion Starter · #17 ·
This thread is really confusing lol...

If you take the throat to throat measurement and add 1.75 or mark it to the front of the riser (or back of bow in trad terms), the measurement will be relatively close. Not enough to cause the weight variance you cite in your OP.

I'd guess that particular issue has more to do with riser geometry and possibly Sanlida being scaled at 26" as I believe I have read that before? I know I've read they generally come in much heavier than the expected weight. But that is not first hand experience
Hah yep, could've got off to a better start. I explained it badly.

Interesting what you say about Sanlida scaling at 26". Didn't know that. Riser geometry is definitely a major factor for variance yes.

I reckon it can vary a lot if you use the back of bow method. A somewhat extreme case, grip depth differs a lot from say an English longbow, to even a recurve with a fairly standard grip depth like a Bear Cheyenne. Between my narrow throated Slick Stick and F261 there's about a .3" difference at grip.

When I bought my Slick Stick in Germany and was asking the rep about string angle, they asked me for my draw length from grip throat to nock, a number I've always used as my "true" DL. How I and many learned it.
 

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Hah yep, could've got off to a better start. I explained it badly.

Interesting what you say about Sanlida scaling at 26". Didn't know that. Riser geometry is definitely a major factor for variance yes.

I reckon it can vary a lot if you use the back of bow method. A somewhat extreme case, grip depth differs a lot from say an English longbow, to even a recurve with a fairly standard grip depth like a Bear Cheyenne. Between my Slick Stick and F261 there's about a .3" difference at grip.

When I bought my Slick Stick in Germany and was asking the rep about string angle, they asked me for my draw length from grip throat to nock, a number I've always used as my "true" DL. How I and many learned it.
I am only stating that guys on another poplar forum have mentioned their Sanlida Athletics 7 limbs scaling much higher and when measured they seemed to match up at a 26" rating. I have no personal experience either way.
 

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The Archery Trade Association was founded in 1953. One of their goals was to standardize various aspects of manufacturing archery equipment and they adopted a standard for measuring draw length as being the measurement from the string to the throat of the grip, plus 1.75 inches. Even most archery manufacturers outside of North America recognize and follow this standard so why the confusion?

The wingspan method has always been a way to estimate a person's draw length and is just that, an estimate. I'm not aware of any manufacturers who utilize the wingspan method.
 

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Discussion Starter · #20 ·
The Archery Trade Association was founded in 1953. One of their goals was to standardize various aspects of manufacturing archery equipment and they adopted a standard for measuring draw length as being the measurement from the string to the throat of the grip, plus 1.75 inches. Even most archery manufacturers outside of North America recognize and follow this standard so why the confusion?

The wingspan method has always been a way to estimate a person's draw length and is just that, an estimate. I'm not aware of any manufacturers who utilize the wingspan method.
I personally wasn't even aware of this USA standard until discovering AMO itself a few years ago. TBH I'm not sure if the AMO DL is most used by a lot of folk in trad, at least outside your particular country. Rather, I suspect it's the back of bow method or 'grip throat to nock' method (bowyers have specifically asked for this). The back of bow method is to me the least useful, as it's error prone due to the vast difference in modern riser designs. It's basically bow specific. You could see 1" of difference easily across different risers, from English D longbows to chunky wood recurves.

For sure no bowyers would use the wingspan method, but plenty of archery 101 courses do, because it's a quick and easy guesstimate.

As I see it "What is your draw length?" without referencing the method leaves plenty of room for confusion, or at least unexpected results. I'm personally taking on the AMO DL as default to save myself some confusion. I will also be sure to clarify with bowyers when they ask, and also folk citing their DL when I'm helping them out.
 
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