ACE Spine Selection

[Blackadder]

Hi All, Need some help.

Just getting back into shooting after 18 months or so 'off' (shot maybe once every 2-3 weeks. Now back to my usual 300 arrows a week and am now sorting the tuning.

Before I went off, I made a few changes to my set-up but I never got around to tuning them in properly as it was mid outdoor season. Switched the rest for a Beiter, changed strings to 14 strand D02 from fastflight and generally messed about with things.

Problem is, now I'm back shoointg I can't get the darned thing to tune

Holding 40lbs at 28" and shooting 620 ACEs, but the bare shaft test keeps coming up very weak. Even with the strongest spring fitted in the button and it dialled so far in I can't get the spanner on it, the bare shafts are impacting maybe 6 inches right of the fletched at only 20yds - go back to 40yds and they are nearly 3 feet off right and fly in a big spiral! I can get them to tune by winding down to 37lbs, but that's not really an option (I want ot go up, not down)

Easton's shaft selector says that these shafts are good for 45lbs at my draw length (in fact it recommends I shoot weaker 670s), and with my old set-up I had them tuned nicely (although they where slightly weak on a medium spring).

Questions for you mighty brains:
1. Help! What's going on?
2. Anyone else shoot 620 ACEs at 40@28" - if not, what do you shoot?
3. If I buy 570s, will they be stiff enough to sort this or do I need to go to 520s (i'm not sponsered, so blowing 240 quid on a new set only to find they are also too weak would be a bit of a bummer)?

Help!

No way should a 28" 620 be weak. The 14 strand string will have an influence here as it will be very fast. Most people I know shoot 670 or 620 at the weight you do? Why a 14 strand string?? seems very light for such a heavy bow?

[Jerry Tee]

Can you try lighter points? Will the lighter weight get the distance?

[joetapley]

The spiralling suggests a clearance problem. Hard bullet to bite but would suggest first replacing the Beiter rest with say a Hoyt stick on (that's assuming you've already tried rotating the nocks). I've also heard that bending the Beiter finger forward can improve things.

An alternative option is adding weight to the centre serving in some fashion to see if that could be a solution. (it will lose you arrow speed of course).

Can you try lighter points? Will the lighter weight get the distance?

Jerry - lighter arrows go faster and will improve sight marks.

[SimonW]

When you say 28", do you mean the length of the arrow?

My arrows are 29.25" from pile end to nock groove.

I have a Helix riser which means I've lost a bit of draw length (compared to my Avalon) but my clicker is just on the bow. This means that my effective draw is just about 28" (i.e. from nock groove to centre of button).

Anyway, my limbs are G3 mediums, 40lb and my actual draw weight (measured with the Easton bow scale) is 40.5lb.

I have shot ACE 520's (120gr pile), ACE 570's (100gr pile) and now X10 550's (120 gr pile) with this setup.

The 570's were too weak, the 520's too stiff and the 550's just right.

I was happier with the 520's than the 570's (sold these) but the 550's are spot on.

Obvioulsy all of the above is particular to me, my style and how I've setup the bow.

However, I do see a lot of people who seem to be erring on buying what I would consider shafts that are too weak.

Given the choice I would always buy a shaft one size stiffer than I needed unless of course I knew what I wanted exactly.

If it was me, I would get the 570's with your setup, unless I knew that I was going to be increasing my draw weight to say 43lb in the next 6 months or so, in which case I'd consider the 520's (dilemma time!!).

If you can, try some (even if they're an inch longer than you would shoot).

Always put the heaviest pile you can get in the shaft.

Just my opinions of course but I suspect that most of us have this problem.

Simon

[SLOWHAND]

What pile weight are you shooting. I'm about the same poundage and draw length as you and my Ace 570's with 120 grain piles are on the stiff side of perfect. Can you get your arrows cut down any? Even half an inch would help. Are your limbs aligned and is your centre shot correct?

[moo-mop]

I think i've previously posted this but: I am like you in that easton recommend ACEs that going by the bareshaft come out too weak.

My choices are between 470 and 430 @ 29 1/2 inches (drawlength measured to 1.75 inches in front of button, it would be less using easton's method) and 47lbs. Easton say 520s. 470 bareshafts come out quite a bit right of fletched shafts and the 430s about right.

BTW I tried cutting 1/2 inch off the 470s, it did not make the bareshaft test come out any differently, so my experiement disagrees with Slowhand's.

I will probably shoot the 430s in competition, although I recently did a pb with the 470s; shooting with either shows no statistical difference in my scores as far as I can tell. I would say that most others using 430s have longer draw weight and/or poundage and I do not understand why mine seem to be different.

[WhitehartFB]

Hi Blackadder

What points & weight, fletchings, nocks and nocking point (floss, beiter or brass) are you using as all will have a bearing on the spine of the shaft as will your release and your current shooting form.

The spine charts will only get you part of the way to selecting the right spine for you.

A 14 strand F/F string will make a difference of about 2-4fps to a 16strand and seems a bit light to me(although not uncommon) 16/18 is the norm for a stable shot.

Wrongly spined arrows cannot be adjusted using the button this is a fine tuning adjustment (also quoted in Rick's book and Precission Archery)

I know it sounds silly but first check your centre shot is set up correctly.

Then you can look at perhaps stiffening the arrow up assuming you cannot make them shorter your options are lighter points or heavier weight at the
nock end (heavier nocks and or fletchings). NB Quick Spin vanes are almost 3x's heavier than standard vanes.

If all else fails and I see that you are in Bedfordshire it might be worth your while popping over to Perris Archery (sorry for the blatent plug) but we have what we still belive is a unique service carbon arrow selection by trial shooting fletched and unfletched arrows with one of our qualified staff to get the right spine for you.

I want to get some ACEs for my recurve, too. According to the Easton charts for my draw length and bow weight I should get either 520 or 570R.

I want my arrows to be an inch longer than my draw length, so should I now go for a stiffer shaft or stick with what the charts are currently saying?

Originally Posted by timujin

I want to get some ACEs for my recurve, too. According to the Easton charts for my draw length and bow weight I should get either 520 or 570R.

I want my arrows to be an inch longer than my draw length, so should I now go for a stiffer shaft or stick with what the charts are currently saying?

When you chose arrows your draw length ( recuve) has nothing to do with it as such. It's the actual length of the arrow that matters.

You could have a draw length of 26" but still shoot heavy spined 30" arows if you like. What is your bow weight ( on your fingers) and what arrow length do you want ( nock groove to the end of the shaft)?