Shaft Spine

jimmy250favre · 07-02-2008, 10:45 AM

This is a question I should know, but I'm not 100% sure of the answer, and its really bothering me. What has a more stiff static spine, a shaft with .300 or a shaft with .500. For some reason, I have been drawing blanks and cannot remember or recall whether or not the bigger number is stiffer, or the bigger number is less stiff. Now, I'm not referring to manufacturers' labels such as Carbon Express 350's or 250's. I'm referring to the actual calculated spine you read on charts. Any replies are appreciated.

Shoot Straight!

davepjr71 · 07-02-2008, 11:17 AM

Typically, 300 is stiffer than 500. Some manufacturers may not follow that rule. However, some manufacturers have their arrows marked 200, which is actually the weakest spine, and the number increases as the spine gets stiffer. For example if it has 340 on it the spine is .340 inches. 400 means a deflection of .400 inches. The stiffer the arrow the less deflection and typically the lower the number.

check out the literature for a manufacturer to make sure before purchase.

SwampCollie · 07-02-2008, 11:40 AM

Quote:

ORIGINAL: davepjr71

Typically, 300 is stiffer than 500. Some manufacturers may not follow that rule. However, some manufacturers have their arrows marked 200, which is actually the weakest spine, and the number increases as the spine gets stiffer. For example if it has 340 on it the spine is .340 inches. 400 means a deflection of .400 inches. The stiffer the arrow the less deflection and typically the lower the number.

check out the literature for a manufacturer to make sure before purchase.

Right on.

Easton is one of the few companies in my opinion that do it right... and that is because they give you a straight up number... they just drop the decimal.

Then you have makers like Gold Tip that use poundage guidelines (CX does this with some of their lower end arrows)... such as 45/60 or 55/75.... its confusing as all hell...

I must admit that in my young dumb days I had Easton Epic 400s... I shot them all to hell and went to (forgive me) Wal-mart to purchase something to replace them. I knew I needed a 400... but I didn't see 400... I saw 60/75 and 45/60 and so on and so forth... so, using novice rationale... I found a 30/50... I figured that if you dropped the last 0 on 400 you got 40 and 40 is right in the middle of 30 and 50..... The arrows just barely fit... they were 28" inches long... I was shooting a Hoyt UltraTec at 29.5" and 73#s with a 28" arrow made for 30-50# draw weights with a 100gr head.... I'm lucky I didn't catch one through the arm.... but good Lord she shot fast buddy! Nobody believed me when I told them my bow shot faster than the IBO speed... but of course I was breaking the rules.... Dang I was lucky and dumb!