Again and again it happens that certain spine values of wooden arrows are not available. Naturally, this is an issue of frustration for the archers who need the unavailable spine value. But here the mistake often lies with Mother Nature!
The spine value of a wooden shaft depends on the area of growth of the timber, where the trees grow exactly, as well as various other influences.
Of course we can try to get a variety of spine values by spreading the areas of growth when purchasing the raw wood. Mostly this works out pretty well. However, there is never a guarantee that we get all the spine values that we need. At Bearpaw Products, spine values are measured fully automatically with an ultra-modern spining facility. Our spine figures are absolutely accurate at Bearpaw Products. No compromises are made here.
Jerry Dishion, the owner of Rose City Archery (manufacturer of cedar shafts), once made a striking statement concerning this issue:
“If you think everything is alright,
Mother Nature gives you a kick in the bottom!”
Wood is a natural product and it can never be guaranteed that exactly the spine values that we need are available. Thus spine values higher than 40 lbs are often quite difficult to obtain for shafts with a diameter of 5/16 inches. At the same time, spine values lower than 45 lbs are often just as difficult to obtain for shaft of a diameter of 11/23 inches.
As already said!
In the purchase of wood and when correcting the shaft diameter minimally (max + / – 0.2 mm), one can make certain optimizations.
But you can never know!
Wood is a part of Mother Nature.
And Mother Nature is unpredictable.