Optimum length longbow

Asafan

New member
I have attentively read messages at a forum (and has received a lot of pleasure :fruitcake ), but have not found discussion of optimum length longbow. On the one hand there are restrictions on length ELB Rules (rather reasonable from the engineering and historical points of view). On the other hand the superfluous length of a bow at a small draw reduces speed of an arrow and increases hand concussion.
I did many gaugings force/stretching of a bow, measured speed of an arrow etc.. Tomorrow I will illustrate the reasons.
For now I ask to tell those who knows: what length ELB it is necessary to take to the girl with a draw 24 "and arrows 26"?
Andrey
 
D

Deleted member 7654

Guest
I'd go by the old fashioned measurement of 'as tall as the archer' !
That will give plenty of draw length and be historically reasonable.
Out of interest I have a lovely symetrical Maple stave with some natural recurve on each limb. So I'm making it into a longbow...it just happens to be 89" long. :mind-blow
I expect the linb length/mass will make it slow, but conversely the length will mean it's draw weight increases slowly, so it can start at a higher initial poundage thus storing more energy.
I shall make it the same poundage at 28" as my Yew bow, so it will be fun to compare the two.
It will probably get shortened and re-tillered at some point.
It will be an interesting experiment, it will also probably be capable of an extreme drawlength 32" or so. :)

Del
 

Asafan

New member
Here by way of illustration a question I will result 2 drawings. The first - a F-D curve of a bow 76 "in the length. A bow 76 # on 32" draw.


The second - curve speeds at different weight of an arrow and a different stretching. On a horizontal - weight in gran. Fat circles - values of speed at 10gran/pound.


Certainly, gaugings are not absolutely exact. And certainly longer will live a long bow at a small draw. Where a golden mean?
This bow has been made of a casual stick of a hazel grove specially for testing. A bowstring - 14 threads B-50.
 

Asafan

New member
If this bow to mark 63#&28 "is will represent the facts. If to write 55#&26" - too it will be true. But the matter is that such use longbow will give a bad throw and will tear a hand. But it is possible to give a guarantee on selfbow 3-5 years without worrying about breakage. Problems of the marksman will be left in the basket!
 

nelly

New member
Good to see someone going about things scientifically for a change.

If you are of exactly average build your arm length will be a proportion of your height hence the rule of thumb that you should shoot a bow about your height. However like most rules of thumb this doesn't work for every one. I'm 5'11" (71") but my draw length is only 25". I just happen to have short arms. When i first started with ELB i was told 71-73" was what i should get. It took me about three years and ?200 to work out this was incorrect for me.

I now shoot bows of around 68-69" which are a lot quicker and because they aren't asked to bend that much i don't get much stacking or hand shock which is usually associated with shorter bows.

If the person has a draw length of 24" i would suggest 66-67". GNAS and BLBS allow ELB as short as 60" for an archer using less than 27" arrows. This rule has been around for donkeys years so i think you could argue a shortish ELB was still a LB!
 

tinkerer

New member
As far as arrow speed goes, I think there's a straightforward rule linking optimum nock to nock bow length and draw length. So a 50lb@28in flight bow must be made 66 ins long (more or less).

Any shorter and the bad string geometry reduces energy storage and much longer and the bow becomes too massive. Maybe you know this stuff already.

So, at 24ins drawlength, the bow should be the minimum 60ins for max speed, but then speed isn't the only thing and durability and comfort would be improved by adding on a few inches- maybe 66ins.

I'm 5ft 10ins with a short 26in draw and like a 71in bow.

David
 

Asafan

New member
David, certainly for a bow tournament it is necessary to be guided by long use. It is a question not of flight! I consider as an empirical rule length of a bow to take 2*draw length +12...14 "depending on tiller and used wood. Even if to include anchor change on 2 ", it will be added +16". That is for draw 24 "the bow will be in the length 24*2+12...16=60...64". It will be good to work with an arrow less than 27 ".
It it is necessary to understand an archer at the order or bow purchase. After all at the dealer other reasons. And loss of speed at the expense of superfluous length of a bow is great... At the sizes specified above stack does not come, that stability has suffered.
 

nelly

New member
24x2+12---16 is an interesting equation i haven't seen before. Its sounds about right for calculating the absolute min length for a ELB. But as David says its not just about speed. I think if you made a ELB using this calc it would be great for flight shooting but a bit unforgiving for target.

In general there seem to be an awful lot of overly long ELBs out there which as you say is probably driven by bowyers trying to minimize returns rather than making an effort to replicate traditional shooting. Im pretty sure most of the Victorian ELBs that are still in one piece are quite short compared to a modern ELB

In short if you want to shoot long go short, if you want to shoot short go long and if you want long life go long. That should make it nice and clear!!!
 

Asafan

New member
So. The majority Victorian ELB 19 centuries, known to me, have length 59-61 "for the lady, and 68-71" for men. But when I see at the lady growth 5'8 "a bow in length 70 +" with marks 40&24 ", I have questions...
 

medieval dave

New member
warbow/longbow length

hi all 1st reply and all that
i have always been told that the length of an english warbow is either 82 0r 83 inches nock to nock so the length of a longbow will be anylength shorter.
also in new money anywhere from 5 foot up
dave
 
Top