85lbs Osage Selfbow Layout?

[cool_98_555]

Hello everyone.  I have a beautiful straight osage stave that I can't wait to get started on.  My draw length is 30" and I am aiming for a minimum of 85lbs.  Please note that I am not looking to adhere to the strict rules of the ELB with the rounded belly design in the D shaped cross section.  I am looking at a flatbow design.  I use 30" arrow shafts and I draw the full length of the arrow.  Right now my favorite bow is a 75lb hickory sapwood selfbow made out of a board that is 60" and can be drawn to my 30" draw length but with a bit of finger pinch.  I have thought about the layout for this bow and I have come up with some proposed dimensions for it:

1) Length tip to tip:  70" ( I would like to go shorter if I can, but I want to accomodate for the 30" draw, so I am open to 70")
2)Handle section:  4" (1" above center, 3" below center)
3)Length of fades from handle:  1.5"
4)Width of limbs at fades:  1.5"  (I think 1.75" would be sluggish in this design, but many have told me that wider limbs were good for osage selfbows in flatbow designs)
5)Taper: 1.5" at fades, taper to 1.25" at midlimb, taper to .5" at tips.
6)Thickness:  5/8" parallel limb thickness for starters
7)Arrow shelf will be cut into riser, preferably center-shot

Knowing my draw length at 30" and my desired minimum draw weight of 85lbs, I am most curious as to the length of the bow, width of the limbs at the fades, and taper design I should be looking at here.  Any suggestions for these dimensions in particular would be very much appreciated!  Thank you!
-Dustin

[Marc St Louis]

If the Osage you have is of good quality then you could safely make it 3 or 4 inches shorter than the 70" you have there and 1.5" is a bit wide. If you want 85# then you should start with a bit more thickness than 5/8".  Everything else sounds ok

[Joec123able]

If you watched Dave canterberrys video on YouTube where he makes an Osage bow his was only 60 inchs with a stiff handle and his puled over 70 pounds at 28 inchs so with Osage 70 inchs long with that draw weight no problem at all !

[simson]

You don't need 70" for an osage 85#

Here is a 58" long and 80#/28", measurements are listed

http://www.primitivearcher.com/smf/index.php/topic,36225.msg476616.html#msg476616

[Marc St Louis]

If you take a look at the bow I posted called Pyramid Elm you will see that this bow is 67" long and the arrow I am using is fully 29" long to base of point plus I am drawing past the base.  This is what a 30" draw would/should look like and what you would be drawing to.  Elm is a tough wood and I could have made the bow a couple inches shorter but to go much shorter than that would stress the bow considerable more which would compromise it's durability.  The draw weight is not an issue

[cool_98_555]

Hello again!  Thank you everyone for your prompt replies and your valuable advice.  It is greatly appreciated.  The stave is of really nice quality, and is rare for osage.  There are no knots, no twisting, and most of the rings are medium, so it is a very nice quality stave.  I have no problem going to 1.25" for the width at the fades, and I am thrilled that I can go shorter.  Before, when I was thinking up the layout for this bow, I had thought that I would have to go with at least 70" because of the 30" draw, but I would be much more comfortable with 66".  What thickness would you all recommend I start with before tillering to get 85#?  .75" perhaps?

Thank you everyone for your wonderful replies.

[Marc St Louis]

Go with a width of 1 3/8".  Best to start off with a bit more thickness than too thin so go with the 3/4"