all people know wood fibre is very short and weak or soft and it is solid not hollow,so,people use spine tester to measure their spine for precise shoot,it has "snake action" fly line to target.
but bamboo fibre is very long and stiff and hollow,so,it has almost nothing "snake action"fly line,it fly like rocket,and it is hollow,so,its flyline is directly and float to target,so,it is faster speed and more precise to target.
western people always shoot with spined wood shafts is very scientific way,and their mind is habbit for it,why we sort our bamboo shafts into spine group is satisfying their habit mind.
in fact we do a lot of testing:during 50 meter,we shoot with 50 # bow with 30-70# spines bamboo arrow,and their result is 99% same.
bamboo arrows in china already thousands of years,never 1 chinese shoot with spines bamboo arrows.if 20-30 meter shoot with bamboo arrows is same results with vaired spined bamboo arrows.we say such as:
50# bow,you can shoot 30-70# bamboo arrows.
at least if you want to shoot more precise,if you use 50# bow,you can choice 40-60# spined bamboo shafts ,and during 50meter,they are same results.
japanese and korean bamboo arrow are sorted with weight only,not spine,and they have also thousands of years bamboo arrow exprenced.
if somebady have interesting to study it more deeply,advice you repeat my testing way:shoot 50# bow with 30-70#bamboo arrows,and if you have good quality camera,you can see if they have very few "snake action" fly line.
