60" ash bow?

[jasper]

I have been working on a bow made of white ash.  I may have asked this before but it is going very slowly.(time is limited).  It is pyramid stle bow from a tree stave.  It is 60" long,  2" wide at the fades tapering to 1/2" at the tips.  I am trying for 55# at 26" It is thru the floor tillering, started tillering and then piked it.  I have  the limbs working almost right to the handle because of the short length. . My question is can this wood and design handle the length.  Should I consider sinew backing it as I do have some.  I have never sinewed a bow but I do have enough to do it.  I may need instruction later if that is what I need to do.

Thanks.

[Minuteman]

You said pyramid style so I assume it has a narrow deep handle section , non bending right? 60" is a short bow in my book 'course I can't tiller worth a hoot so I need extra length to spread out my mistakes.
 Other more experienced forlks will chime in soon.

[Hillbilly]

A little longer would be better with ash, but you might be able to pull it off, especially with a 26" drawlength. If I was trying for a 60" ash pyramid from the start, I would probably make it 2 1/4"-2 1/2" wide at the fades.

[adb]

Hi,
55# and 60" might be a bit of a stretch with an ash selfbow. Pyramid design is perfect for what you want. It's asking quite a lot, but if you tiller it carefully, you can probably pull it off. Get all the limb bending, right from the fades. Keep the profile rectangular and the belly flat, and you will distribute the stress over the entire limb. You might end up with more than a couple inches of set, but no big deal. Flat bellied whitewood pyramid bows can be real hard shooters, with decent cast. Good luck!! If you break it, try again!

[jasper]

I want a decent bow out of this.  Would 45# or so be better to min. set.   With a lighter weight and less set, could it perform as well or better than more weight and more set.

[Eric Garza]

Hi Jasper,

To address your earliest question, I'd sinew back it.  Or at least rawhide back it.  Sinew backing, in particular, can help reduce string follow and prevent raising a splinter and, inevitably, ending up with a broken bow.  You might also want to decrown it, if the bow has significant crown to begin with.  Don't be too afraid of string follow, a little doesn't hurt.  It gives the arrow a softer send-off and makes the bow a little easier to silence, at least in my experience. 

All the best,

-Eric

[bootboy]

Just to ask a question that I have always wondered. Besides the beautiful look of the pyramid style bow what are its merrits?

[Kviljo]

I've made a 60" pyramid bow from a board of american ash. It is probably 50-60# at 26", and has only followed the string 1". No heat treatment. The board had pretty good growthrings though.

Just make sure to tiller it to stress the wood evenly along the whole limb, and keep the wood as dry as you can, preferably below 8%.

[adb]

Pyramid style bows are great for the so-called second string whitewoods, such as: hickory, ash, maple, etc. They're wide at the fades, up to 3" or more, tapering to narrow nocks, to keep limb tip light and fast. They are flat (rectangular in X-section), and this will distribute the stress over the entire width of the limb. A wide, flat limb is strong... optimal for marginal wood. Look at any modern bow, recurve or compound, the limbs are thin and wide and flat. This is the most efficient design, storing the most amount of energy, and releasing it efficiently, as well.
Lots of people poo-poo pyramid bows, and criticize them for poor cast, and being "dogs." However, lots of people also say "oooh", when they shoot a well tillered flat bow for the first time. They also last pretty well, casting thousands of arrows.
Also, like Eric said, don't worry about string follow too much. A bit is actually a good thing. A bow with a bit of set is sweet in the hand, and is soft and quiet to shoot. Set really has more to do with the type of wood, and how the bow is tillered, than how heavy it is. I  have a 70# 62" hickory backed osage, with less set than a 35# 68" hickory selfbow. I agree... if you want to sleep at night, insure your home... and back your bow. Cheers!!

[Kviljo]

Just for the fun of it: 

A rectangular cross-section bow is not the best for most woods, as they are usually stronger in tension than in compression. Therefore a trapeze-like cross section is stressing the bow better, where the back is narrower than the belly. However, it is not as safe as a rectangular cross section.

Plus, a straight taper, round tillered pyramid bow is not the most efficient design. Far from it. A well tillered narrow tipped holmegård is much more efficient.

Although I like the pyramid-style, especially for flatbows, as it is easy to make, and very easy to tiller almost perfectly, using a small piece of a board with a pencil through it. That makes a very durable bow