The common way to measure draw length.

[Zradix]

hey everybody.

I'm not trying to    

[CoilSpring]

Most common way to measure DL is the AMO Standard and is from the bottom of nock to deepest part of grip + 1.75" (the AMO definition).  The 1.75" may or may not always measure to the Back of the riser, because every bowyer's bow risers/grips are shaped differently.

When a bowyer says 45#@28" it USUALLY means the bow weight will be 45# when drawn 26.25" from bottom of nock to the deep part of grip - this assumes an AMO defined draw of 28" (ie. 26.25" + 1.75" = 28" AMO).

I would expect you to have measured your draw length just like you did: 29.75" is your draw length.  Mine is 28.5 inches, if I anchor properly (26.75" + 1.75" = 28.5" )

Yes, your AMO draw lenght is 29.75" (ie. 28"+1.75"), so if YOU draw an AMO-bow rated 45#@28", you'll draw that bow 1.75 inches further than where its 45# weight will be, so you'll be holding about approx 51# of weight at your draw length.

USUALLY, when you see a bow that says 45#@28" it means at an AMO draw of 28" (26.25 + 1.75) the bow wt is 45#, but, yes, some very few bowyers do measure their bows differently, so just ask the seller to measure bow weight on a scale when drawn either to your draw length (so you'll know what YOU'll be holding) or drawn to 26.25" from the string to the deep part of the grip (so you can compare apples to apples)

Clear as mud, huh???

[JoeM]

I just learned something.  Thanks!  Joe

[Rob DiStefano]

i have no time or patience with measuring risers, arrow shelves and handle depths.  i measure draw length from the depth of the arrow nock to the forward most part of the riser back.  this makes checking weight easy - a full length shaft that's marked at 26" to 31" from the nock depth, in 1" increments, put a clothespin on the 28" mark, nock and draw the shaft with a bow scale 'til the clothespin hits the riser.  that's the bow's 28" draw length holding weight.  period.

for the very most part, almost all bows are off in actual draw weight by +/- 1# to 5# (or more!).

imo, "draw weight" is a guideline of sorts.  if you notice that much "stacking" effort in drawing a bow, for example between 27" and 29", that bow has -imho- "issues".  a good bow will have a very smooth drawing transition 'tween a 3" draw length variance.  and it will perform about the same within that drawing range.  so a few pounds more or less holding weight typically won't matter all that much to almost anyone. ymmv.

[Orion]

Coilspring provides an excellent explanation.  You'll notice that the AMO way of doing it and measuring to the back of the bow often yield identical results, with sometimes a quarter inch or so difference.  That translates into less than 1/2# of draw weight. So it really doesn't matter if you measure/express your draw length using the AM'O method or measuring to the back of the bow.  The results are so close that they make no practical difference.

[cbCrow]

A real easy way to determine your draw, without all the confusing tech stuff, is to attach a spring type cloths pin to your arrow and simply draw to your anchor. Measure from the throat of your nock to the closest edge of pin and that is your draw. An easy way to calculate your weight at draw is to take 28"-brace height, than take that # and divide you bows weight by it. Example; your bow weight is 45@28, assume a 7" BH( use real height) 28-7=21", than divide weight by it 45/21=2.14# per inch. You draw 29.75" so you would add 2.14*1.75=3.74+45=48.74or 49#@29.75". This will give you an approxomate weight at your draw. However you need to use a scale to get true weight as some bows show different amount of stack sometimes even at lesser draws over 28" and yes some are not the weight marked on the bow.

[Rob DiStefano]

oh yeah, all weight measuring bets are off unless the scale used is truly accurate.    :D

[don s]

i do basiclly the same as rob. i mark the shaft in one inch increments from 24 to 30. even though every bows riser thickness may be different the one thing that i believe will not change from bow to bow is the lenght from the depth of the nock to the throat of your grip. it doesn't matter if i am drawing my k-mag or my bbo with a slight locator grip. for me that measurement is 24 1/2" consistantly. so if i were to take that and add the 1 3/4" my amo draw length is 26 1/4. thats only a 1/4" difference from measuring my bbo from the depth of the nock to the back of the bow. that measurement is 26" consistantly. so i just say my draw is 26". don

[Hoyt]

[Night Wing]

I never measure my draw length to the deepest part of the grip (pivot point). That's useless for me. I measure my draw length to what the illustration shows which is in front of the riser (farthest from me).

When I order a bow, I make sure the bowyer and I are on the same page as to draw length and poundage.

[don s]

Originally posted by Night Wing:
 
When I order a bow, I make sure the bowyer and I are on the same page as to draw length and poundage.

despite the differences of opinion on measuring DL. i agree with Night Wing on this point. don

Ditto Rob. Handles are very different so to measure to the deepest part of the grip, then add 1.75 is not reliable.

[Javi]

My draw length is from the throat of the nock to the pivot point of the grip. The measurement to the back of the bow is irrelevant to me, as this can easily vary a ¼” to 1/2” or even more depending on the riser…  Measuring to the back of the bow is a quick way to check that you aren’t collapsing your form but isn’t a static measurement from bow to bow.
 
The nice thing about trad bows is that ½” or so has little affect on draw weight or anything else as long as you anchor in the same place from shot to shot.  The same could be said of draw weight, so knowing the exact measurements or of little consequence unless one wants to use a program like Stu Miller’s.
 
So if a bowyer marks a bow 52# @ 28” is it really a big deal whether they measured to the back of the bow or to the throat of the grip and added 1 ¾”…. It’ll be around 52# at somewhere around 28”… you still have to tune the arrow to the bow, and fine tune the bow to the arrow…

I think there should be consistency in the method, but in the end there is no enforcement body and folks being folks they are gonna do it their way.. But I ain’t gonna worry about a pound or two of draw weight one way or the other…

[Pete W]

AMO DRAW LENGTH STANDARD For Manufacturers
Draw length is a specified distance, or the distance at the archer’s full draw, from
the nocking point on the string to the pivot point of the bow grip (or the theoretical
vertical projection of a tangency line to the pivot point parallel to the string)
plus 1 3/4”. Draw length from pivot point shall be designed at DLPP and shall be
called TRUE DRAW LENGTH.
EXAMPLE: 26 1/4” DLPP plus 1 3/4” is the equivalent of 28” draw.

   For Dealers and General Use
For practical reasons not requiring precise terms, draw length is the distance, at
the archer’s full draw, from the nocking point on the string to the back of the bow
at the arrow rest.

EXPLANATION: The standard Manufacturers is consistent with the Bow
Weight Standard as related to the pivot point. The DLPP plus 1 3/4” is compatible
to previous concepts of draw length. (See handle illustration.)

Draw length for Dealers and General Use relieves the burden of preciseness not required for
general use and facilitates determining arrow length.
THIS STANDARD SUPERSEDES
THE PREVIOUS STANDARD.

[Rob DiStefano]

Originally posted by Pete W:
AMO DRAW LENGTH STANDARD For Manufacturers
Draw length is a specified distance, or the distance at the archer’s full draw, from
the nocking point on the string to the pivot point of the bow grip (or the theoretical
vertical projection of a tangency line to the pivot point parallel to the string)
plus 1 3/4”. Draw length from pivot point shall be designed at DLPP and shall be
called TRUE DRAW LENGTH.
EXAMPLE: 26 1/4” DLPP plus 1 3/4” is the equivalent of 28” draw.

      For Dealers and General Use
For practical reasons not requiring precise terms, draw length is the distance, at
the archer’s full draw, from the nocking point on the string to the back of the bow
at the arrow rest.

EXPLANATION: The standard Manufacturers is consistent with the Bow
Weight Standard as related to the pivot point. The DLPP plus 1 3/4” is compatible
to previous concepts of draw length. (See handle illustration.)

Draw length for Dealers and General Use relieves the burden of preciseness not required for
general use and facilitates determining arrow length.
THIS STANDARD SUPERSEDES
THE PREVIOUS STANDARD.

in the best of all real worlds, your true draw length is from the depth of the nock to the point at which your bow hand contacts the bow.  as an example, that length might be 27".  and to further the example, your arrows are 29" from the depth of the nock to the back of the point.  therefore, since pivot point to back of stick bow distances can vary from 3/4" to 2", you might have some serious arrow overhang, or you might just need a longer arrow.  it's all relative and it's all good.  

[PaddyMac]

Originally posted by cbCrow:
A real easy way to determine your draw, without all the confusing tech stuff, is to attach a spring type cloths pin to your arrow and simply draw to your anchor.

Thank you. Perfect.

My technique involved masking tape on the arrow, a sharpie and a my highly skeptical but lovely assistant.

[dragonheart]

The best way to determine your draw length is actually shooting the bow.  Nate Steen (Sunset Hill) told me about this one.  

Mark an arrow with different colored lines(Sharpie)at about 1/2" increments and shoot.  Shoot natural, like you will in the field.  Have someone watch and notice which color of line is at the back of the bow.  

This does not help you as far as where a bowyer measures the weight of the bow, but it gives you your actual draw length.  When we try to just draw and hold (not release the arrow), it is different than when we actually shoot the bow.  It is, just try the test.  

You may draw and settle, draw more, draw less, when you actually shoot.  The act of shooting the bow, the way you will in the field or on the range is what is important to do.  

I would consult the bowyer on how s/he measures the draw to determine your weight at your actual draw length.  The examples given give insight into how the standard in the industry is measured, but this test gives you your specific draw length.

[cbCrow]

Paddy mac you are very welcome! At least I know that their is one other who believes in the KISS principle.

[Zradix]

Thanks for the replies everyone.
I was thinking he grip to nock was the most common.

Good to know when you're wrong.

Thanks again