I just got a brand new digital scale. Thought I'd see how close my bows were to what their marked.

Boy was that a mistake. Now I know AMO standards draw to the pivot point, hoping they'll get close to a 28" true draw. Their argument for doing that seems pretty weak.

I also know they are to be marked plus or minus a pound.

I can't find a bow within 4 pounds of what's marked. I drew them all to a blocked distance of 28 inches at the front/true draw length, but you would think that something would be close.

I suppose the new scale could be off, I'm going to get a calibrated weight to check that, then I'll know.

That would help First thing you should do

Yep. I weight my bows. I have a spring style scale for my bows. One day I'll upgrade to a digital scale. Some of my bow's weights are right on what is marked and some are one or two pounds off.

It's measured to the pivot point at 26 1/4"....not 28" to the pivot point. Anyway, the AMO measure is for manufacturers to use to create a standard of sorts, but it's still hit/miss for many of them, as it was back in the day. I don't make bows for anyone, so I measure mine to the back of the sight window...just as I have since the mid 1960's.....not 26 1/4" to the pivot. Although it should be relatively close when you add the 1 3/4" from the pivot to the back of the sight window to get a 28" number.

I never found it to make any sense anyway for everyday use, to take two steps to accomplish one measure. What my bow is, is what it is, no matter where I measure it to, and as long as I'm consistent with where I measure to, it doesn't matter squat.

Are you measuring in such a way that the physical weight of the bow is being measured?

Are they 4# heavy, or 4# light?

Are they all off the same amount? If not its not your scale.

Ooops, and yes, I measure all my bows on a Hanson spring scale that I've had since 1976. It's still pretty much spot on and can be calibrated as well.

26 1/4 to the inside of the grip is true draw or to the spring button hole on compounds. But most bowyers measure to the far edge of the shelf because thats how most customers measure. Amo says it can be 2 lbs off plus or minus..... 50,51,52.....53,54,55

Fdp that makes no difference. The distance the physical weight pulls it is the same as if you pulled it, so is the weight.

I measure all my new bows. Most are spot on with only 1 being off out of 6 new bow between me n my son. It was 6 lbs off so I sent it back.

Yes I measure mine and they are usually either on or with in a pound or two. My scale is a Hanson and I'll also check it. We had a certified scale at work so I could weigh my test weights. In fifty years I've only had a few bows off weight by three or more pounds. Also measure to the back of shelf.

Actually if the weight of the bow is on there and the scale isn't zeroed it does make a difference by the physical weight of the bow.

Try measuring them hanging and also horizontal on a table. I have done it both ways and there isn't a lot of difference. That said I always do mine horizontal and use a boat winch to pull it so I can lock it at intervals for force/draw information.

Jus -

Get the scale calibrated (some 10# barbell plates are enough).

Most of mine are within AMO specs of a few pounds off, except for older DHs, which are usually 5# to 10% heavier than marked.

With a hanging scale, the physical weight of the bow is irrelevant, since the scale is weighing the downward force, regardless of where it's coming from.

I use a LAS draw board and digital scale (about $200), just because I'm lazy.

Viper out.

Yes, I always weigh mine--both the draw weight, as well as the overall bow weight. My draw is 30", and with some bows it's quite surprising how much extra draw weight comes into play once you go past 28". I have a 49# Groves Prestige Magnum that registers 59# at 30"; also a 52# Hi-Speed that goes up to 61.4# at 30".

Those are the exceptions, however. Most of them pick up an extra 5-6# when drawn to 30"...which is quite nice when you add it to a 50# bow. That extra 2" of draw turns a deer bow into an elk bow.

to calibrate your scale ... 1litre of water = 1kg

All of mine have been scaled. All the Bears are spot on as marked. The others close enough. I just mark an arrow at the specified draw length and draw the mark to the front of the arrow shelf/back of bow. Thats the way we did it 50 yrs. ago,and the way I still do it.

I weigh every bow that rolls through here (not many anymore), most were right on. Our 3yo twin grandsons got into my bow box a while back and I have not seen my hand held bow scales since. The good news is my missing grain scales have showed up.... I have since purchased a digital bow scale but I have yet to use it.

I made a bow scale out of a luggage scale. Weighted my bows (BW and BL) and several friends. Pretty all much spot on.

RonL

Mine are all within a lb or two, one was 6# strong, don't recall which one, sold it. And no, the weight of the bow does not come into play, same w/ a compound. Like George, I weigh them horizontally & vertically, no difference to speak of.

I have a Hanson Hand Held that I use while making the bow. Jawge

I am scaling mine and even the DH are in +1-2lb industry standard.

You can use water in a bucket as a true weight, this assumes you have a kitchen scale to measure the weight of your empty bucket.

Fresh water weighs 62.4 pounds per cubic foot. 8.33 per US gallon.

I do, and I do a force draw curve.

Hanging the bow by the scale makes no difference. If a 50 dw bow has a physical weight of 2 lbs, it only takes 48 lbs of force to get it to full draw if it’s hanging on the scale.

MP

I do weigh all of mine. I have a drawboard set up with a boat winch to draw the string. The scale is tied to the winch rope. I have a yardstick that I cut and mounted to read 28" at the 26 1/4" AMO standard. I use an electronic scale that is checked occasionally by weighing a five-gallon bucket of house paint that is verified on an old beam and weight type physician's scale. My electronic scale reads .3 pounds light at around forty-five pounds. It is not adjustable without opening it up and tweaking a pot on the circuit board. I don't care to do that. Of the dozens of bows that I have weighed, most are a few pounds lighter than marked. Old Damon Howatt bows are the exception. Most of them are actually two to three pounds heavier than marked.

Read it on here for bow weights ... INDUSTRY STANDARDS are 2#s under to 3#s over.

Very typical process in industry, i.e., like horsepower ratings, a 100hp OB motor must be +/- 10-% of the rating to wear the 100hp decal.

Such stndards are actually driven by the Fair Trade in Commerce Act.

Not many of my bows are 1 3/4" thick, and they can vary in thickness a good bit, but for the sake of my own continuity and simplicity I weigh them all at 26.25" to the deepest part of the grip and write that exact weight on them as (63# @ 28") for instance.

I scale mine with a digital scale with the scale hooked to an eye screw horizontal and the bow vertical like it’s being shot. I measure to the edge of the shelf and all my bows have been pretty spot on except for one pervious one. One thing I also do is take a thick leather flap with a hole in it for the scale hook, as wide as my fingers and grab the string with it under the nock to simulate what a 3 under pull may feel like. I find the weight may go up by 1 lb that way.

Too much record and math for me. ??

I do! my Nightshade is 21oz, Longnight is 19oz, 17" ilf with XXL limbs is 2.8lbs...

Oh... you meant draw weight? I measure them at my draw. A bow could be marked 30@28 or 90@84 and it wouldn't be what I'm drawing. I could go with out markings at all and not be bothered.

Small variances in things like measurement tools and style can account for a few lbs. 1/4" can vary your reading 1/2lb or more. The difference between the small hook on scales and 3 finger flap is noticeable. I use a 2" flap to simulate my 2 finger draw.

I kinda want to mark my bow 90@84 now. 30@28 90@84 still 42@32 for me.

Always.

I use a digital crane scale.

As a matter of fact, I just finished shimming the limb bolts on my ILF riser to get a set of limbs to the draw weight I want them to be.

Rick

That's what I'm using Rick, a new digital crane scale. And I just cross checked it's calibration with my digital kitchen scale and a 10 pound barbell. Exactly the same.

This all came up because the latest bow I bought is marked 45 pounds and weighs in at 49.8 pounds.

I understand all bows don't get built to an exact standard, what I don't get is why they don't get marked at what they really draw. Are they ashamed they didn't hit weight or what?

Hey Bruce. Here are the pictures of my string strap I promised you.

Doing it this way gives you a more accurate draw weight measurement of what the actual weight is on your fingers.

Rick

Good idea Rick

Bruce, I've seen the actual draw weight off (low) by as much as 5# on a hook as compared to on the fingers. The average is about 2#.

I learned that trick from Kirk Lavender at Bigfoot Bows.

Rick

I made the leather gizmo, and weighed a bow. 1.3# increase. Going into Thanksgiving feeling more studly.

I always weigh bows and do a dfc for the last 4-6". I use a calibrated Salter Brecknell spring scale. 2 of them actually. 1 goes to 55#, I use it for lighter bows. 1 goes to 110# for heavier bows. Scales are the most accurate in the middle range of what they weigh.

Actual bow weight is very important to me. I have a lot of bows of certain models in 1-3# increments. A 43# bow might be 47# for me; a 47# bow might be 45#. I can never tell by the weight written on the bow! If 2 bows are the same actual weight I only keep 1.

Aside from different methods of scaling or pulling the string, and scale calibration I've found that a bow's weight varies up to a few #s... depending on the temperature and use! If the bow is in cold weather when I scale it, it can gain 2-3#s. And vice versa. Also, if the bow has been strung, e.g., overnight, or drawn to full draw 3-5 times or shot before weighing, the weight goes down. If a bowyer has been tillering a bow and scaling it repeatedly in a short time, and then comes up with a final weight it will be less than if the bow sat unstrung for a day was then scaled. If I scale a bow 5 times in a row, each time the weight goes down slightly. Now I take a bow to full draw or past it, 4-5 times, before taking the weight.

That is a great idea Rick!

I weigh all of my selfbows many times while tillering...after that they are all "about 50 pounds"... :) Happy Thanksgiving.

Yes.

So, I read these responses, and two guys mentioned hanging physical weight didn't matter...ummm. Hanging physical weight is just that, physical weight, not drawing weight. If you have a hanging weight of 6 pounds, that's the weight you feel in your hands, not the drawing weight.

Just to see, I stuck a bow in a hanging scale, 6 pounds physical weight, 60 pounds pulled straight down. Moved the bow to the bow press and draw board, bow is vertical, not horizontal, cranked the bow back to 28", and weighed 53.8 pounds...ummm The verticle bow is measured without the mass physical weight that you'd be getting if you didn't set the digital scale back to zero once you hung the bow in the scale. I grabbed a brand new Hoyt Ventum, pulled it out of the box, 70 pounds at 29". Like they all come in from the factory. Put the bow into the press, cranked it back 29", into the stops, 69.6 pounds. Hung the bow in the hanging didital scaled, hanging weight of 4.4 pounds, pulled the bow into the stops without resetting the scale, 73.3 pounds. Ummm... Tell me again that the mass hanging physical weight doesn't matter....

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