which has a greater effect on spine- arrow length, centershot or point weight?

[ozy clint]

been struggling a bit with tuning my buff setup. i have 2 sets of limbs for a riser i have. i bought a 2nd hand riser to go with my 69# limbs that i hunt buff with. i've been trying to get it tuned for over 2 months and i'm still not 100% sure they are right yet. i tune by trimming my arrows as i have a set point weight that i shoot. so to confirm a change is needed i screw on a lighter point weight or pack out the side plate to see if i'm still weak and if doing this made a difference i know i'm right to trim the arrow. trouble is i don't seem to notice any difference. i find it real hard to come to a conclusion as to what needs to happen. is spine so much more sensitive to arrow length than point weight and centershot. i build out the side plate heaps and drop plenty of point weight and nothing seems to change. maybe i'm over thinking things. it just seems i've got to have perfect form and release to get them to fly like darts.

so what do you find?

[Blaino]

What was wrong with the arrow you used to take the buffs you wrote about in your last article? Seemed to work great!  

[pseman]

I find that carbons are more sensitive to changes in arrow length than point weight. I tend to shoot center shot or greater bows because they just seem to be more tolerant of arrow spine.

Although others experiences may differ, I find I get better/more consistent arrow flight with an arrow that is on the stiff side of tuned rather than weak.      For me, weaker arrows tend to tail whip more with a less than perfect release.

[BWD]

All of the above, but length must be very close on carbons.

[AWPForester]

I think a carbon is very tolerant of point weight once you have achieved the perfect length.  and I think the length is easy enough to find when you consider riser cut.

I agree 100 percent with pseman.  It seems that if your bow is cut to or past center,  They will take any point weight you want after you get the length right.  And length shouldn't be a factor with those riser cuts.

Now on longbows, the riser cut is everything.  I find that if I am short of senter I have to drop spine because I keep them trimmed tight.  But once again, when I get the length right, I can shoot 125-250 points no problem.

Just giving a piece of advice, if i had your setup, a 7595 in the gt traditional, cut with one inch trimm, 100 grain brass insert, 250 grain head, and a weight tube would be awlful good medicine if that bow is cut to center or more.  Good luck and God Bless

[Owlmagnet]

ozy clint: I do not disagree with anything I've read; I just shoot wood and am not that familiar with the nuances of carbons. The point I want to make is that you mentioned finding a used riser to, in effect, "build" a second bow.

The first thing I would do is ensure that the tiller and the brace height of my "new" 69# Bob Lee was an identical match with the tiller and brace height of my 54# Bob Lee. Then I would work on building a heavier arrow that would match the trajectory of my 54# set-up--that is, if I wanted to continue to hunt with either bow, interchangeably, (the size of my quarry determining my choice of weapon)....

Be well and good luck.

[ozy clint]

blaino- they are the same limbs on a different riser i bought 2nd hand. i want to keep these limbs with this riser from now on. when i 1st put them on the tune had changed and i've been tuning ever since.

i played with the brace height tonight. i will do some more shooting to see if it made a diffence. failing that i'll guinea pig an arrow and keep trimming it and see if it gets better.

how much do you trim before you notice a difference? 1/4", 1/8"?
thanks guys.

[tradtusker]

Clint are you bare shaft tuning?

Length has the biggest effect on spine IMO.
I do not play with the Center shot much, I do not want to manipulate the bow to fit the arrow. I like the bow to be forgiving and quiet and then tune the arrow to it.

You will notice very little difference by changing point weight.

I start with the bow set-up, I make "sure" the arrow is long and weak with the point weight of my choice. Then I bare shaft tune and start cutting the arrow down (1/4") to get the spine right.(stiffer)

Don't shoot to close this is key..start at 30m and once your fletched arrows and bare shafts are hitting the same place move back to 40m and repeat. If very close but still noticeably off, then start cutting less 1/8". Once its "on" I put a broadhead on the fletched arrow and it should hit the same place and the other shafts.

[Ben Maher]

Originally posted by tradtusker:

Length has the biggest effect on spine IMO.
 

x 2

[cacciatore]

Yes with carbon lenght is the major factor in arrow tuning.

[bianchijon]

I've had the same thing where no matter what I change it doesn't effect the spine of the arrow when I bare shaft tune. It has always come down to the arrow hitting the riser or arrow shelf. Sometimes it is really hard to tell because you can't hear that little tink when the arrow goes or because the arrow shoots pretty well and groups well. One test you can do to find out is put a Hoyt super rest on. It is just double sided tape and you can take it back off. If you can tune it on the super rest but can't tune it on the shelf then the arrow is hitting the shelf.

[Easykeeper]

I've found it is a combination of point weight and shaft length.  If you want or need a heavy point, the shaft will end up shorter than if you want to use a lighter point.  

I like to tune my arrows to shoot 175 heads, mainly because I have a lot of them.  I start full length and cut back until I get good bare shaft flight with that weight.  Once I get there, I get a stiff or weak reaction if I go up or down in point weight.  I haven't found an arrow that was insensitive to point weight, it's always a combination of point weight and shaft length in my experience.

I agree that carbons are very sensitive to length changes, sometimes 1/8" will be all it takes to get the change you need.

[bubinga]

The Bob Lee is cut 3/16th past center.  I have found that I can get good results out of a wide variety of arrow combinations with my Bob Lee.  Both bare shaft and paper tuning.  It is just not a sensitive as my bows that are not cut as much.

[ozy clint]

thanks guys. you confirmed my suspicions that one has to make big point point adjustments to notice any difference.

andy- i owe you a beer. you convinced me to go back to the basics and they are flying alot better. i have trimmed about 3/4" today. last thing today i screwed on a big magnus I and i think they are just slightly still weak. a hair more trimming and i think i'll be done.

thanks

[tradtusker]

[kawika b]

Where is Shawn Leonard? He's got some good experience with carbons and spine tuning... always citing the quicker recovery of carbon. With that said, arrow length seems to make everything else need to be more in-line if you go just a little too long or too close to being too short.