Why chase rings in some woods and not others?

[ccase39]

Just curious. I know it's a must for Osage and Osage is a pretty strong wood. Why not hickory? Also how do you treat white woods differently. I have a sweet gum sapling curing.

[huisme]

Some woods don't have large crunchy rings of early wood between rings of late wood and have their pours spear throughout the rings evenly- those are defuse-porous woods like maple. Still other woods have sapwood strong enough to be fine backings, even for laminate bows, like hickory, ash, or maple.

Locust and osage on the other hand have much stronger heartwood than sapwood and are ring-porous so they're easy to chase to one ring of heartwood for the back.

[PatM]

It's all about the heartwood versus sapwood suitability of the wood.

[ekalavya]

i think the reason is efficiency .... however it does not matter when the draw weight is too low
(for example 15 or 20 lb works for nearly all ) and the bow is too long , too broad ....

the sapwood & heartwood thing was already mentioned by PatM .

The sapwood, usual wood and so on of some wood species is close or in fact catastrophic.

well , it's already answered ....

[Badger]

   You need to have an uninterupted growth ring on the back of a bow with almost any wood you use. Some woods you can just remove the bark and have the back of the bow using the sapwood but you are still chasing a ring, if you damage the back removing the bark you will have to chase down one ring. So in a sense you do have to chase rings regardless of the wood. Yew being an exception. I nkow lots of bows have been built from hickory, elm and degame with violations but it is not recomended.

[Pat B]

With woods like osage, locust and mulberry you would typically remove the bark and sapwood and chase a good, clear ring for the back of the bow. With whitewoods like maple, ash, hop hornbeam and others you remove the bark and use the ring under the bark as the bow's back. It is preferable to cut whitewoods during the growing season, when the cambium layer is active and the bark will peel off easily, exposing a pristine bow back. Your goal when building a bow is to have a back with no violations. The strength of a bow is in its back where the tension forces are.
 There are some grain configurations in boards that are appropriate for bows so, even though there are grain violations from sawing the wood, they are sound enough to build a bow with a good chance of it surviving.

[Del the cat]

There aren't many woods like Osage where the rings are like alternate cast iron and chalk. The difference between early and late growth is usually much less dramatic and thus the need for exact growth rig following less imperative. Take Yew and Hazel as examples. Yew is evergreen and is growing more or less all year round. Hazel is deciduous, but starts putting out catkins before the leaves have fallen, it barely stops growing and has V indistinct rings.
Del

[ccase39]

Makes sense thanks guys

[bowandarrow473]

Hickory sapwood is  the strongest you can get where as osage heartwood is the strongest wood.