Correct way to measure bow poundage

[FrankM]

I read online where some measure it from the back of the bow (calling this your draw length) and some from the belly of the bow. Which is the correct way?

[wingnut]

It should be measured at a point 1 3/4" towards the back of the bow from the deepest part of the grip.  Meaning that the deepest part of the grip is 1 3/4 and 26 and 1/4 back from that is 28".


This is the AMO measurement accepted as industry standard.

Here is a link to those standards.
 http://peteward.com/AMOStandards.pdf


Mike

[LBR]

Something that is often overlooked is the scale.  Bow shops generally use a hanging spring operated scale that are often inaccurate.

I believe certain longbows are measured from the back, they have more than a 1&3/4" grip. The Bear dealer that I went to tested their hanging scale with two 25# weights. They used a small wood finger simulator and weighed the bow with it hanging from the string, because just a hook gave a false draw length. The physical weight of the bow is the draw force at that measurement.  If it is hung with bow up top, it measures the draw force plus the weight of the bow.m

[Bjorn]

I measure to the back and regularly recalibrate my scale with dumbells of a known weight. The bow is clamped to my tillering tree and pull down on the string so the physical weight of the bow it not involved.

[rraming]

Originally posted by Bjorn:
I measure to the back and regularly recalibrate my scale with dumbells of a known weight. The bow is clamped to my tillering tree and pull down on the string so the physical weight of the bow it not involved.

I calibrate the same way. Have heard some guys talking about vertical vs horizontal draw weight measuring- you don't want gravity messing you up - don't know about that one.
I always wondered is some bowyers use draw from front of riser and some use deepest art of grip plus 3.5" (or whatever it is).

[damascusdave]

I like the method the AMO gives for dealers and general use, that is simply using the measurement to the back of the riser...I shoot at somewhere between 29 and 31 inches so 28 inch draw weight means little to me

DDave

[**DONOTDELETE**]

Typically all bows weight measurements are taken from the back of the riser to the string at the arrow nock location.

Actual AMO draw length is like wingnut discribed. (see drawing below)

There are considerable differences in draw weight when using a straight hook or a simulated fingers hook. It depends on the bows design.

For example.... My static recurve design measured with a fingers hook like the photo below at 50@ 28" i would have to draw to 28.5" with a straight hook to get 50#.....

A D shaped long bow at the same poundage you may have to draw it to 29" with a straight hook vs a fingers hook.

 

 

[LBR]

Getting down to the brass tacks, you would have to measure the bow with the fingers of the actual shooter, or a simulator that same size.  It can vary a good bit depending on the hand size of the archer, hence the "standard".

[bamboo]

DLPP--makes the most sense to me--but here's the wording--
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.

I also found this---

AMO CONVENTIONAL
BOW WEIGHT MARKING STANDARD
In accordance with the AMO Bow Weight Standard, the manufacturer has the
option to mark his bow with actual draw weight at 28” (26 1/4” DLPP) draw or to
use the following bow weight markings, especially on hunting models and middle,
and low end bows.
Example: Bows weighing 19 - 20 -21 lb. - will be marked 20 lbs.
Bows weighing 22 - 23 lbs. - will be marked 20X lbs.
Bows weighing 24 - 25- 26 lbs. - will be marked 25 lbs.
Bows weighing 27 - 28 lbs. - will be marked 25X lbs.
Bows weighing 29 - 30 - 31 lbs. - will be marked 30 lbs.
All other conventional bow weights not shown would follow this same formula.