i want to measure a bow,s weight. all i have is a hanging scale.if i put the bow sting in the hook of the scale with a arrow on the string,and i put a mark on the arrow at 28",and pull the bow toward the floor would i need to stop (at my mark) on the belly ,back, or center of riser to find the true weight? any input would help ,thanks so much

Two different measurements I think, but a lot are measured to the back of the bow.

ok thanks i was not sure if was center of riser or even with back of bow thanks beacon

What measurement do you want? First, hang the bow in such a way that the weight of the physical weight of the bow is not going to be on the scale.

Then, if you want the AMO measurement, you move the string 26,25" from the pivot point (deepest part) of the grip. The back of the bow is meaningless.

Now, if you want to measure YOUR draw length, you have someone mark an arrow to the back of the bow when you are at full draw, and then weigh the bow to that draw length.

Measured from front of the bow that's why you leave longer with broadheads or you would cut your shelf off. Let alone your fingers.

fdp's method of 26.25" from the pivot point is how it is done.

The distance from the back of the shelf to the pivot point varies a great deal from bow to bow and is not used.

That's why many people often say Howatt's are marked lighter than they are. People measure them 28" to the back of the shelf and they should not.

When I measure draw weight I hang the bow on the scale and then tare out the bow weight. Then I measure to the pivot point.

Agree that fpd is correct re the AMO measurement, but 26.25 inches to the deepest part of the throat assumes a throat thickness of 1.75 inches (i.e., the back of the bow is then 28 inches) and is often expressed as draw weight at 28 inches. Measuring to the back of the bow yields very close to the same result most of the time.

Most bows have a throat thickness somewhere between 1.5 and 2 inches, so most will be within a quarter inch of the 1.75 inch grip depth assumed with the AMO measurement. A 1/4-inch difference in draw only amounts to a half-pound or so of draw weight. Not enough to worry about.

fdp also raised another issue, i.e., whether to include the weight of the bow in calculating the draw weight. If you put the string over the scale hook and pull the bow down to 28 inches, the bow weight is incorporated into the draw weight. The way to avoid this is to hook the bow to some immoveable object on a horizontal plane and pull the string horizontally rather than vertically. This yields a heavier draw weight (the weight of the bow, which now isn't incorporated into the measurement) at the same draw length.

The fact that folks, including bowyers, do it one way or the other explains why bows aren't always the weight we think they are. We just measure draw weight differently.

Like i said 2 ways, I wasn't sure on the exact measurement ffrom pivot. Still, the difference between the two methods are probably statistically negligible. Sure is a lot easier to measure to back of bow, eh?

It is easier to measure to the back of the bow Mike. But I wasn't sure if he is wanting to check the AMO weight on something either.

My bows measure from 1-1/2 to 2-1/4 from throat to back. I only own 5 bows. There are maybe 1000s of different bow designs, and I'm sure some have both bigger and smaller measurements than mine. This is why AMO was created, so all bows would be measured the same. Because of this all bow draw wts have been measured at 26-1/4 from the throat of the grip since 1968.

MP

AMO standards list the two ways mentioned above to measure a bow's draw weight.

Measuring to the pivot point 26-1/4" and adding 1-3/4" is what the manufacturers should do.

Measuring to the back of the bow is recommended for dealers and the general public. This method gives a person his true draw length and the weight of the bow at his draw length. bvd

Frank, you were correct, and very precise. I couldn't explain it as well :>)

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