need tuning explanation....

[klingville]

I have a tuning issue that I would like to understand, because I just can't wrap my head around it.

I shoot a 64" Deathwish longbow, 49@28, 7" brace.  The shelf is cut to about 3/16" before center.  I have a 26" draw.  Therefore I figure I'm pulling about 40 lbs. (I have used a fish scale to check my draw weight and it ends up about there - not sure how accurate that thing is though....).  I received two strings when I bought the bow (direct from Deathwish), but I don't know what material they are made from. (I have tried to contact them about this, but have received no reply....)

The arrows that I shoot spine out stiffer than what I would expect. Given my draw weight and shelf cut, I would expect to need a spine in the 35-40 lb range.

However, I am shooting a Trad Only 600 carbon arrow with about 190 grains up front cut to 28.5" BOP.  According to Stu's calculator, the spine is around 46 lbs.

Someone recently gave me a few 3 Rivers cedar arrows 35-40 spine.  I put 125 grains on the tip and they didn't start flying decently until I cut them down to 26" BOP.

I'm satisifed that I can get arrows flying straight, but I would like to understand this....any thoughts?

Thanks,
Jeremy

[JRY309]

You can't compare carbon with wood or aluminum,carbons are just are a different animal.They react and recover quicker from the paradox.The calculator can give you help,but the final testing is done by the shooter.

[joe ashton]

here is  how I do mine.  I start with a shaft that I think will work or the Stu calculator suggest will be good and leave it long.  With out feathers I shoot it at 10 yards.  If it is weak I'll cut off 1/4" and shoot it again.  If it is still weak I'll cut off another 1/4".  I keep doing this until it flies perfect or (oops)is too stiff. I tend to keep my life simple, so when I get them to fly I call it good and go shoot...

[Wolfshead]

Not an expert by any means in fact I am just starting out myself
but it sounds like the spine is too weak for your bow and cutting the arrow down helped to stiffen them up making them fly better
can get better answers from the more knowledgable people here I am certain

[Orion]

You're probably drawing closer to 44# if you're drawing 26 inches.  I think Steve generally puts fast flite type strings on his bows.  In wood, you probably need 45-50# spine