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Discussion Starter #1
I guess I may just be looking for clarification here. I was reading a previous thread about carbons and saw that Flying Dutchman posted that the poundages listed on carbons are for compounds....

I am about to pick up some goldtips and certainly don't want to end up buying something I can't tune. My stats are #63 @ 31 1/2, I want to have my arrows as close to full length as possible and shoot 145gr or 175gr heads. I was advised by the archery guys at a local bow shop (who deal 99.9% with compounds) that a 5575 goldtip would be appropriate, but after reading the earlier post that would probably put me a bit overspined....right?

Do I need to go 3555?

Thanks,
Jethro
 

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Discussion Starter #2
Oh, I guess I might add that I am shooting a Tolke Whip r/d longbow, but it is cut pretty close to center...not sure how much that factors in.

Thanks,
Jethro
 

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Jethro,

keep in mind that full length GT's is starts with 55-75. As we saw, 55-75 equals an AMO spine of 78 lbs.

Now lets take a look at your bow. It's a modern reflex deflex, so you can add 5 to 10 lbs to the drawing weight (assuming you shoot a Fast Flight string). You pull close to 32 inches, which adds another 20 lbs to your poundage (5 lbs per inch longer then 28 inches). You are at 63 lbs, which makes a total of 93 lbs (63 +10+20) for dynamic spine!

I would even take a closer look to the 75-95 wich delivers an AMO spine of 103. You want to shoot with a 145 or 175 grains head. This will weaken your shaft and that's exactly what we need in this case. 175 is 50 grains havier than a 125grains head , which substracts 10 lbs from your dynamic spine (5 lbs per 25 grains more then 125 grains), giving you a spine of 95. It even becomes sligthly less when you take the insert of 15 grains into account...

You end up so high because you have a very long drawweight.
This should be pretty close. Ofcourse this is all theory, only real shooting will tell the truth....:wink:

I think that a 55-75 (78 lbs) will be to weak.

Having typed this, I tried Stu's Miller spine calculator afterwards.... http://heilakka.com/stumiller/ It agrees.....
 

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I forgot: the GT 75-85 will give you appr. 9 grains/lbs, which is a safe amount above the absolute minmum of 8 grains/lbs.
 

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Discussion Starter #10
If I wanted to increase my point weight or use brass inserts, say 50 grains, would this arrow still work for me?
 
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