underdrawn bows

[Dante_F]

So i am noticing a theme with some longer bendy handle bows is that the bow isnt being drawn to its full length like a 56 inch bow not getting a full 28 inch draw, are there any advantages to a so called šunderdrawnš bow?

[DC]

Are you meaning that a bendy bow 'should' be drawn to twice it's length or was that just a coincidence?

[Badger]

 One advantage to shorter drawing bows is that they take less set and tend to be more efficient even though they may not store as much energy. Once a bow is overdrawn a couple of times that slight advantage is gone forever.

[Dante_F]

ok that makes sense, giving it a bit of room so it doesnt take set or lose performance

[George Tsoukalas]

Yes, or break. Jawge

[Pappy]

Not sure where 28 became the standard for full draw,or any thing else is call under drawn or short draw ??  not many folks I know actually draw 28.I think it was just a standard set by mass produced bows. If I am building a bow for myself I never pull it over 26 which I consider full draw  Like Steve said no reason to bend it more than I need, on the other hand if building one for a person that draws 30 I never pull it over 30 which is full draw for them.
 Pappy

[lonbow]

Books from the early 20th century speak about a standart arrow of 28 inches including the pile. That gives a draw length of about 27 inches. When talking about 28 inch arrows, it sees very easy to assume a 28 inch draw at some point!?
The draw weight was measured at 26 inches from the belly side of the grip and not to the back during that time. This doesnt seem to be a bad idea, because there are bows with flat and bows with deep grips. The distance from the nocking point to the belly side of the grip always stays the same.

lonbow

[Del the cat]

Books from the early 20th century speak about a standart arrow of 28 inches including the pile. That gives a draw length of about 27 inches. When talking about 28 inch arrows, it sees very easy to assume a 28 inch draw at some point!?
The draw weight was measured at 26 inches from the belly side of the grip and not to the back during that time. This doesnt seem to be a bad idea, because there are bows with flat and bows with deep grips. The distance from the nocking point to the belly side of the grip always stays the same.

lonbow

Hmmm... not sure any of that is true. 
If you bear in mind most archers would draw to the back of the bow and not beyond (the exception being flight archers).
The distance from nocking point to belly doesn't "always stay the same"... take a bow measure the draw length to the belly... glue a 1/2" extra to the grip/riser the draw length to the belly has now changed but the draw length to the back has not.
Apologies if I have misunderstood your post in some way..
Del

[bradsmith2010]

if I make a bow for myself,, I make it to shoot at 25 inches, that is the full draw for that bow,,no matter what the length,,of the bow,,

[DC]

This is making me think that I could make a "better" bow by just tillering it/them to my draw length rather than 28". Is there an accurate way to extrapolate the 28" speed from a 27" measurement? Would just a percentage work? Would it be a fair assessment since I'm not actually bending the bow fully?

[lonbow]

Thats exately what I meant, Dell! The distance from the belly side of the grip does always stay the same, because the every archer has his own drawing length. But you need a longer arrow using a flatbow, because the grip is deeper. Using a bow with a bending grip section, the arrow can be shorter. So I need 27 inch arrows for a longbow and lets say 27,5 inch arrows for a flatbow. The draw length stays tge same but the arrow length needs ti be different with different kinds of bows.

[bradsmith2010]

DC,, I am sure there is a way to extrapolate the 28,, Im sure Badger knows,,
but yes your bow designed for and shot at the shorter draw will be better than,, tillering to 28 and shooting at 27,,
I think you will be pleased with the speed you get at 27 ,, 26 or 25,, if the bow is designed for that,,

[Dante_F]

oh, i guess i didnt really factor in the persons draw length, just what it is theoretically able to reach, ok makes sense now

[Badger]

This is making me think that I could make a "better" bow by just tillering it/them to my draw length rather than 28". Is there an accurate way to extrapolate the 28" speed from a 27" measurement? Would just a percentage work? Would it be a fair assessment since I'm not actually bending the bow fully?

  DC, suppose you had a bow that was drawing 47.5#@27" and shooting at 186. If you drew the bow to 28" it would be drawing say 50# ( 2.5# gain) suppose your bow is about 75% efficient. That would put you at about 188 with a 500 grain arrow as opposed to 186 with a 475 grain arrow drawing 27". But keep in mind that extra 1" draw will also cause some set in most cases possibly eliminating your speed differential. If this were the case the loss of speed would be reflected when you went back to 27" and shot it again.

[Woodely]

I tiller my bows to 28" and further so I know it will at least handle the extra pull to 29".  It just gives that added extra insurance in the hopes of not breaking or taking to much set.  My bows are 64" plus.