Help understanding TBB wood bending test

[ryder]

Hi guys, I was wondering if you might be able to help me understand the math behind the wood bending test in the traditional bowyers bible a bit better. For those of you who use it.

I have a stave that I took a sample from, and tested a piece of in accordance with the test in the TBB.
The results are: 36lb at 3 1/4 pull, taking 1/4 set, and breaking at 4"

If I'm reading it right, that means the wood has a higher draw weight than standard and needs to be narrower. But if you follow the math in the book and divide the 'standard' draw weight of 25 by 36 you get 0.694, and when you times that by the standard limb width of 1.75, you get 1.215.

That means it is recommending a limb width of 1.22" to make a 50lb bow out of this wood.

I'm still learning my way around bow building, but my instinct is telling me that is way too thin to make a 50lb flat bow out of?

Thoughts?

[SLIMBOB]

What type of wood?  Not to narrow if it's Osage.

[ryder]

Its a variety of bloodwood. It has a tight interlocking grain, and growth rings that are hard to discern. It does not split cleanly and has a strong tendancy to check if the logs aren't quartered quickly.

Ive attached a pic of some, for interests sake. The bit in my hand was from a quarter log offcut that wasnt dried correctly, but it shows the end grain.

[SLIMBOB]

No experience with that wood so I cant answer specifically.  1 1/4 inch  wide is not too narrow if the wood is right.  I have built lots of Osage bows at that width so its very doable.  I will say that if your new to this and I believe you are, my advice would be to over build them from the get go.  If your bend test says 1.25 go 1.5 on the layout.  You can always narrow it some if you need or want to, but you cant add it back if it starts to take set.  Someone will come along with more info on that wood and give you some specifics Good luck with it..