Hmmmmmm

During this far too long, cold and icy winter, I have been wondering about a couple of bow-related things and thought that maybe either someone has a good answer to my questions or someone can direct me to a past thread with an answer.

1st question is this: when bowyers determine the draw weight of a bow, do they adjust for the tare weight? What I am finding is that most of the bows I own or have owned, hit the draw poundage with the weight of the bow included,  not adjusted for tare. My digital scale is pretty good and I pull down on the bow to 28" of draw to get the weight. When I adjust for tare, the draw weight is inevitably lighter than indicated on the bow.

2nd question: I often read that "modern" recurves and longbows outperform bows of the past--assuming this is a comparison between composite (glass and wood) bows, is this due to materials or to design and what exactly are we talking about? Speed? How much? or is this in comparison to all-wood bows, or bows w/o carbon laminations?

So-- any answers or informed speculations are appreciated.

[ChuckC]

1)  Well, to find out, flip the scale system so the bow is hanging.   I am gonna assume that when measuring a (draw)force that far exceeds the weight of the bow itself, the "tare" is not an issue.

I am waiting for an answer for the second question.

Great questions Susan

B T W  a certain packable seat seems to fit my hind end perfectly, thank you !

ChuckC

[Hermon]

This is how I look at question #1.

If the scale is hanging from the ceiling and you are pulling down to measure the draw weight, the mass weight of the bow is part of the force needed to draw the bow.

Now if you were to devise a way to have the scale running horizontally, and the mass weight of the bow to be held somehow and measure the draw weight, it would take the same amount of force.  It would just be that you are providing all the force and not the mass weight of the bow and gravity helping.  

In other words, the force required to reach 28" would be the same either way you measured it, but it is just coming from different sources.

The mass weight of the bows I shoot the most is only about 1 1/4#.  Spring scales could easily differ by that much or more.  Digital scales should be more accurate, but I don't think I personally could be able to tell the difference.

[Mike Mecredy]

I hang the bow on the scale, zero it out, then pull it to the draw length where I'll mark it.  That way I don't get the physical weight of the bow in the draw weight. The physical weight of the bow has nothing to do with what spine arrow you use, or the energy stored in the flexed limbs, so I eliminated it.

[T Folts]

I use a digital scale also and it weights 1.25lbs.
I hange the scale hit zero and add 1.25lbs to the draw weight of the bow. Are you counting for the weight of the scale?

[Orion]

Though others may do it differently, Hermon is correct.

Regarding your second question/statement, it would probably be correct if the word "some" or "most" were judiciously applied, i.e., some modern bows outperform some bows of the past, and SOME don't';  even most modern bows outperform most bows of the past, but not all do.  

A lot of the old Howatts, and similarly designed Jack Howards, will shoot with any of today's glass laminated recurves.  There are other bows of the past that also shoot as well.

Very little has changed as far as design.  However, some of the newer materials do lead to increased performance.  Carbon is lighter and more efficient than glass.  Probably the biggest change is low stretch strings.  However, they can also be used on older bows to really step up their performance.

Yep, it is a long winter. A wet rain/snow outside as I write.

[mike g]

How far in the past are you going with these bows....For comparison..?

[JamesV]

I don't think there has been much improvment in performance between the 60's production bows and today's bows, all things being equal. Only a huge jump in prices and that is understandable. I admire the oldtime boyers, they got it right and their designs are being copied by almost everyone building bows today.

T folts--, no, not the weight of the scale. when you hang the bow and zero out the weight, that is adjusting for tare.

On the "modern" bow issue-- has the composition of fiberglass changed at all since the 1960s, or are we able to taper laminations to get a faster limb in a way they couldn't do iut then? As I recall most of the Howatt bows had maple cores, and I think the Bear and Pearson bows did as well. Now we are often using other core woods, how much performance difference does that make, or is it mostly for looks? Just wondering...

Chuck, was that the treestand seat? I forget...

[ChuckC]

Susan, yup, that strap on seat with the post out the bottom.  It works well for that which I was wanting to do.

Snowing off and on here too.  Good thing is, we lost a lot of snow in the last week, and more warm weather is forecast for the next several days.  Spring really is here !

ChuckC

Sure hope you're right--we're stir crazy here!

[KeganM]

The performance thing comes from two places: first comparing to the bows that Hill and his contemporaries used for most of their careers (selfbows or all wood composites). Today's bows out perform then, and recurves especially have become considerably more forgiving and accurate.

The second part is comparing modern composites to older composites. There it's not so much about the materials, other than the leaps and bounds in high performance strings and modern tips, as much as it is just building upon the foundation of design laid by the forefathers of the modern composite. Not every bow today shoots better, as a matter of fact there are still plenty of dogs being built as far as speed and shock, but when you get to the fastest bows today, you don't have toes-over-the-edge designs that will blow up if you're not careful, or a bow that is fast but won't shoot straight to save yor life, or even an expensive bow. It's just learning from those that came before and incorporating the design features you want to create a really nice bow. Again, not everyone is following the high performance path, and that's fine, but if you did want a bow for hunting big game, you can safely use a little less in poundage... or bigger broadheads    Learning from others and growing is a fantastic part of archery!