How thick do I need to make this bow to reach 50# - 55#?

[toomanyknots]

If the bow is a 62" nock to nock Red Oak pyramid bow with a 6" nonbending handle, width 2 1/2" tapering to 3/8", how thick should it be to reach 50# - 55# at 28"? I'm thinkin 1/2"... What about at 57"? Would 7/16" thickness at 57" length with a 6" non bending handle give me 50# - 55#?

[Hrothgar]

If it were hickory I would say those dimensions would be close, although I would probably go more like 3/4" for the width at the base of the nock. Also with a shorter bow I've found I can shorten my draw length a little, say 26", and still have a comfortable, deadly weopon.

[toomanyknots]

I meant 5/8", opps,

[sulphur]

I would say 7/16 would be close.  start at 1/2" and start tillering.  BUT, first i would say stretch that thing out to 66.  I usually don't push red oak that hard.  55# is the absolute most i go on a normal length bow.  What is your draw length.  if 26" then i'd say go for it.   A 62" at a 28" draw length bow is pushing for too much at that weight and 57 is scary.  That being said i'm sure it can be done with excellent tillering.

[toomanyknots]

Ya, I know, I actually plan on sinewing. I know I know, If it don't work than 10 bucks down the drain and Ill take the sinew off and use it for glue. I just made a red oak bow 52" nock to nock, 2 1/2" tapering to 1/2" at 3/8" thick. Pulls like 50# at 28" fine. 7" non working handle. I don't trust red oak that much, I was just bored, wanted to try siyahs out for the first time and planned on pulling only to 26" I think it depends on the board more than anything. No, I don't really trust red oak that much though.

[4est Trekker]

You referenced a 52" ntn red oak bow in your last post that had a 7" non-working handle and siyahs that was tillered to 28".  Even without the siyahs, which shorten and highly stress the working portion of each limb, you're only left with 45" of overall working limb (22.5" per limb) and a bow that is shorter than twice the draw length.  Combine that with the siyahs, which I assume are around 3"-4" long each, and you're reduced to 37"-39" of overall working limb (18.5"-19.5" per limb).  An unbacked, unlaminated wooden bow that pulls 28" should be at least 56" in length, except in rare occasions involving the combination of excellent wood, design, and tiller.   I wouldn't even pull at 60" red oak bow of said construction to 28".  I've seen some short bows, but...

Also, sinewing a red oak bow with the dimensions you outlined in the first post would completely crush the oak.  Plus, sinewing a bow over 60" in length is counterproductive because the weight of the sinew trumps it's elasticity at that point.  Combine that with a wide pyramid bow and you'll have wasted a lot of time, sinew, and glue. 

Your signature line is interesting, but those offering you suggestions have collectively broken hundreds of bows and successfully built far more than that.  Their combined knowledge is at least worth consideration, for your own safety's sake. 

[Pat B]

The reason I asked how many bows you have made is because you are coming across like a newby that is fishing for the easy way out and not an experienced bowyer. 

[toomanyknots]

"Combine that with the siyahs, which I assume are around 3"-4" long each, and you're reduced to 37"-39"

I took the siyahs out actually so you wouldn't have to do the math. It is actually 56"

"Your signature line is interesting, but those offering you suggestions have collectively broken hundreds of bows and successfully built far more than that.  Their combined knowledge is at least worth consideration, for your own safety's sake."

lol, I just keep that there for when someone tells me to go make more bows. I think it's funny. Once in a while, only once in a while, I will get a reply that is just "go make more bows" that has nothing to do with the question and is rude. So I'm allowed to be rude back.

""Also, sinewing a red oak bow with the dimensions you outlined in the first post would completely crush the oak."

Have you tryed it? Has anyone? Can anyone give an example of sinew crushing a bows belly period, I hear so much of how you have to be careful with sinew over powering a bows belly especially if the wood is weak, but have seen no examples or heard any stories or anything. I have scowered the net and have found nothing but suggestions to be careful. How am I to know where the line gets drawn. I don't doubt it. But I don't know. So I try. Because you can't know in truth if no one trys. Boomer from paleoplanet made a nice sinew backed red oak bow. Probably wasn't half as short though.

[NTD]

 "Can anyone give an example of sinew crushing a bows belly period,"

I can't give examples with sinew because I've never sinew backed a bow but crushing a belly might not mean what you think it does.  Excessive set would be an example of "crushing" the belly.  Compression fractures or Frets/Chrysals are reported here regularly these are the result of "crushing" a belly.  I guess you don't see a lot of crushed red oak bellies by sinew here because well a lot of us aren't trying to reinvent the wheel and are content to take advice from those who have gone before   You know the old grey haired bearded classics, relics, and whatnot

By the way.  Go make more bows

[toomanyknots]

"By the way.  Go make more bows"

lol , you know what, I think I will.

"I can't give examples with sinew because I've never sinew backed a bow but crushing a belly might not mean what you think it does.  Excessive set would be an example of "crushing" the belly. "

Excessive set in a sinew backed bow?

"I guess you don't see a lot of crushed red oak bellies by sinew here because well a lot of us aren't trying to reinvent the wheel and are content to take advice from those who have gone before"

Here is a post from steve (bagder) which is contradicting what is being said about sinew crushing the belly of wood. Not to call out steve but I think what he says brings to light a contrary view on the nature of a sinew backed bow. He is also one of those guys with experience who I am supposed to take advice from like you said, right? Or do I have to pick and choose,

"Ken, sinew actually is pretty easy on the belly fibers. Even though sinew is pretty heavy stuff it won't net the bow any extra mass. Sinew is best applied where design elements for one reason or another are somewhat extreme. A 31" draw on a 65" bow would qualify for this easily. The sinew has to stretch to get your moneys worth out of it. Sinew is basicaly weak in tension but very elastic so it takes a lot of pressure off the belly. You would be very hard pressed to build a bow that could stretch sinew anywhere near it's limits. I think a 65" or 66" bow drawing 80# could be made to about the same demensions you would normally make a 60# bow. I would go for it ken, your climate will keep the sinew in primo condition. Steve"

From this thread:

http://paleoplanet69529.yuku.com/topic/17286

I mean just to get it out there as I am on the fence as to what will happen. I even think I might try to back a wide bow only 2/8" thick. To see what will happen. Instinct says that from the backing not letting the wooden back stretch out a bit in tension that the belly will be stressed that much more. ? But then again, steve's point comes up about how sinew's strength would be taking the pressure off of the belly compressing and on to the back stretching. But at the same time I have always understood that any backing stresses the belly more. I see that the only factor a sinew backing would have in compressing a belly more than normal is the increase in draw weight crushing it. And would the effect be lessened or amplified, or effected at all by reflexing the bow and then appling sinew?

[aznboi3644]

I believe that the sinew wouldnt be stressing the belly more...but shifiting the nuetral plane to  be using more belly fiber to do the same work.

I actually have a 48" really dense piece of red oak I'm saving to sinew back.

I have found quite a large range in density though...some twice as dense as others but that is the extremes

[4est Trekker]

Why ask these questions if you're determined to argue each and every response?     Is it sufficient to know that jumping off a tall building is not a good practice due to the law of universal gravitation, or must you test it for yourself?  Or perhaps you must search out someone who has to prove your point.  Indeed, many people have built bows that seemingly defy the odds, just as there as those that have survived falling off of tall buildings.  However, I believe you misunderstand the nature of this forum.  Healthy debate is just that...healthy.  Argumentative, pretentious, and unfounded claims with no apparent desire to affect learning do little more than make folks less likely to help those like you in the future.

 I would be happy to answer your questions as stated above, yet I feel it would do little good.  "As iron sharpens iron, so one man sharpens another."  Yet, if you've got an axe to grind, it's best to find another sharpening surface.  Best of luck, my friend.

Blessings,

Curt 

[toomanyknots]

"Why ask these questions if you're determined to argue each and every response?"

Ya I'm not trying to piss you off, so please don't take it that way.

"Argumentative, pretentious, and unfounded claims"

I've made no such thing. 

[sailordad]

well personally i would go about ya wide and then i would go about so thick and call it good 

actually i just thought i would try and put a little humor here seeing as how some folks are starting to ride your back side on this

ive never ever made a bow from oak,so a cant really say on any of it
i would like to try white oak but not red

[n2huntn]

Try the 1/2" . I have made several pyramids with red oak but have not used sinew on anything. I'm guessing you could reflex a little when adding sinew to up poundage if you like.
 I like your willingness to try even if your told it wont work,I sometimes do it too, but presentation is everything. Don't get discouraged or be discouraging . It can get a little heated here sometimes but we all cool down and still share/learn.
Keep us posted, I'd like to see how it turns out. I love short bows.
Jeff