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CARBON ARROW
SPINE APPLICATION CHART
Return to Arrow Specification List
UNIFIED FOR ALL ARROW
BRANDS USING ACTUAL SPINE DEFLECTIONS (FOR USE IN MODERN
COMPOUND BOWS) |
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NOTE: |
This chart is normalized
for typical modern compound bows with IBO speeds between
280-330 fps. For faster bows, read chart one block
down and to the right.
For slower bows, read chart one block up and to the
left. Chart not applicable for traditional bows.
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NOTE: |
Actual arrow spine
deflections do not necessarily match the manufacturer's
marketed spine sizes (Gold Tip 5575, Carbon Force 200,
Carbon Express 60-75, etc.). Manufacturer spine
sizing systems may be arbitrary (100, 200, 300, 400) and
may or may not reflect the arrows' actual spine
deflections. For example, a "Carbon Express Maxima
250" has an actual spine deflection of .404", not .250"
as the sizing suggests. In this case, the rating
system is arbitrary. To be safe,
DO NOT assume an
arrow's spine size is the arrow's actual deflection.
See actual arrow specification data on our
main arrow page
before using this chart to select an appropriate spine
stiffness for your bow. See below for more
details. If you need help, call our pro-shop at
877-410-7811 or
email us for assistance. |
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KEY |
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1 |
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2 |
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3 |
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4 |
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5 |
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6 |
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7 |
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Use
arrows with
actual spine
deflection of:
.580-.620" |
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Use
arrows with
actual spine
deflection of:
.480-520" |
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Use
arrows with
actual spine
deflection of:
.430-470" |
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Use
arrows with
actual spine
deflection of:
.380-420" |
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Use
arrows with
actual spine
deflection of:
.330-370" |
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Use
arrows with
actual spine
deflection of:
.280-320" |
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Use
arrows with
actual spine
deflection of:
.230-270" |
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DRAW
WEIGHT |
LENGTH
OF ARROW |
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85
GRAIN POINT |
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100
GRAIN POINT |
|
125
GRAIN POINT |
|
23" |
24" |
25" |
26" |
27" |
28" |
29" |
30" |
31" |
32" |
|
23" |
24" |
25" |
26" |
27" |
28" |
29" |
30" |
31" |
32" |
|
23" |
24" |
25" |
26" |
27" |
28" |
29" |
30" |
31" |
32" |
|
30-32 |
1 |
1 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
|
1 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
|
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
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33-35 |
1 |
1 |
1 |
1 |
1 |
1 |
2 |
2 |
3 |
4 |
|
1 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
|
1 |
1 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
|
35-37 |
1 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
|
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
|
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
|
38-40 |
1 |
1 |
1 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
|
1 |
1 |
1 |
1 |
2 |
2 |
3 |
3 |
4 |
4 |
|
1 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
|
40-42 |
1 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
|
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
|
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
|
43-45 |
1 |
1 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
|
1 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
|
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
|
45-47 |
1 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
|
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
|
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
|
48-50 |
1 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
|
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
|
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
|
50-52 |
1 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
|
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
|
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
|
53-55 |
1 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
|
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
|
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
|
55-57 |
1 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
|
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
|
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
|
58-60 |
1 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
|
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
|
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
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60-62 |
2 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
|
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
|
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
|
63-65 |
2 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
|
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
|
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
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65-67 |
2 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
|
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
|
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
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68-70 |
2 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
|
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
|
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
|
70-72 |
2 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
|
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
|
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
|
73-75 |
3 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
|
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
|
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
|
75-77 |
3 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
|
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
|
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
|
78-80 |
4 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
|
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
|
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
|
80-82 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
|
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
|
5 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
|
83-85 |
4 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
|
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
|
5 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
|
85-87 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
|
5 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
|
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
|
88-90 |
4 |
4 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
|
5 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
|
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
|
90-92 |
5 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
|
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
|
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
7 |
|
93-95 |
5 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
|
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
|
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
7 |
|
95-97 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
|
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
7 |
|
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
7 |
7 |
|
98-100 |
5 |
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
|
5 |
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
7 |
|
5 |
6 |
6 |
6 |
7 |
7 |
7 |
7 |
7 |
7 |
| |
23" |
24" |
25" |
26" |
27" |
28" |
29" |
30" |
31" |
32" |
|
23" |
24" |
25" |
26" |
27" |
28" |
29" |
30" |
31" |
32" |
|
23" |
24" |
25" |
26" |
27" |
28" |
29" |
30" |
31" |
32" |
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85
GRAIN POINT |
|
100
GRAIN POINT |
|
125
GRAIN POINT |
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FAQ: |
What is
a spine deflection anyway? How is it measured? |
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An arrow's spine
deflection is the arrow's measured resistance to
bending. Basically ... an arrow's spine rating
tells you how stiff the arrow is. As you may know,
arrows should neither be too limber or too stiff.
For proper safety and best performance, the arrow spine
must be matched to the output of the bow. Arrows
which are too stiff or too limber will not fly well and
will degrade the accuracy of your bow. Arrows
which are dramatically underspined (way too limber) can
even present a failure hazard. So selecting the
proper arrow spine is very important.
According to the modern standards (ASTM F2031-05) an arrow's official spine deflection is measured
by hanging a 1.94 lb. weight in the center of a 28" suspended
section of the arrow shaft (not to be confused with the old AMO
standard of 2 lb. and 26"). The actual distance the
1.94 lb.
weight causes the shaft to sag down is the arrow's actual spine
deflection. For example, if a 1.94 lb. weight causes the
center of a 28" arrow to sag down 1/2 inch (.500"). Then
the arrow's spine deflection would be .500". Stiffer
arrows will, of course, sag less. More limber arrows will
sag more. So the stiffer the arrow is, the LOWER its spine
deflection measurement will be. The more limber an arrow is, the
HIGHER its spine deflection measurement will be.
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FAQ: |
Why
isn't there a universal system? |
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Well ... there is ... sort
of. The gold standard for rating arrow spine has
always been Easton's fitment charts. Before carbon
arrows hit their stride in the 1990's, practically every
archer in the world had at one time studied the little
blocks on the Easton chart, trying to decide if the
2219's, 2413's, or 2315's would be better (remember?).
The basic rating system wasn't really hard to
understand. The first two numbers were the arrow's
diameter (in x/64th's of an inch) and the second two
numbers were the shaft's wall thickness (in x/1,000th's
of an inch). So a 2315 was an arrow shaft with a
23/64" diameter and a wall thickness of .015".
Easy enough. But what did that really mean?
The rating system had nothing to do with arrow spine,
directly anyway, and the numbering system wasn't
necessarily sequential. A 2315 arrow was actually
heavier and stiffer than a 2413 arrow. A 2219 was
surprisingly heavier than a 2512, but not as stiff.
And a 2314 and a 2315 oddly weighed the same but had
different deflections. Ok. So it wasn't so
easy. But Easton's engineers crunched all the
numbers and the handy aluminum arrow charts solved all
the woes with their nice little organized blocks.
Then carbon arrows came along and made things easier ...
almost. Since carbon arrows had a much broader
ranger of application, there was no need for 10 to 15 sizes
of the same arrow. For most carbon arrows, 3 to 5
sizes covers virtually every application. So
Easton simplified the sizing system by basing the sizes
on actual spine deflections. Easton's familiar
carbon arrow spine sizing system (500, 400, 340, 300) is
basically the arrow's spine deflection x1000. So a
500 shaft is a .500" deflection. A 340 Easton
shaft is a .340" deflection ... and so on. So
forgiving the shift of the decimal, the Easton spine
sizing system matches up nicely with actual spine
deflections.
Unfortunately, the system is somewhat counterintuitive.
For Easton/Beman arrows, the lower numbered shafts are
actually the stiffer heavier shafts, and the higher
numbered shafts are the more limber and lighter shafts.
This naturally goes against the bigger is more
line of thinking. Since most people don't know how
spine deflections are obtained, or why they matter, some archers will simply
buy the "larger" size for heavier bows and "smaller"
sizes for lighter bows. Of course, this is
completely backwards. So we all ultimately ended
up back at the Easton charts studying the little blocks.
And why not? No archery pro-shop is complete
without a big Easton chart on the wall. So why
mess with tradition?
Turns out, Easton wasn't the only player in the carbon
arrow game. In fact, they were one of the last to
join-in when they purchased Beman in 1995. By that time,
Gold Tip already had a five year head start with their
popular graphite arrows. And Gold Tip had really
simplified things with an easy 3 size system ... the
famous 3555,
5575, and 7595. The system was intended to be
self-explanatory. The 3555 roughly fit a 35-55#
bow, a 5575 fit a 55-75# bow, and a 7595 fit a 75-95#
bow. At least that's how most archers understood
the sizing. But this wasn't always the case.
The Gold Tip arrows had spine deflections of .500"
(3555), .400" (5575), and .340" (7595) respectively.
So a 53# bow shooting a 30" arrow actually required the
5575 spine (per the Easton gold standards anyway)
instead of the 3555 the sizing convention might suggest.
So it wasn't long until Gold Tip published their own
charts (yes, with the little blocks), based essentially
on the Easton spine deflection data. And much to
our dismay, Gold Tip tends to reinvent those charts
every other season and shift some blocks around a space
or two (which invariably sends a few of our customers
into a panic attack over which block is really theirs).
To be fair, Gold Tip's system really wasn't so bad ...
comparatively anyway. There was worse to come.
Not to be outdone, Carbon Force Arrows, a
division of PSE, decided to really simplify things and
make their sizes completely sequential ... 100, 200,
300, and 400. So the larger the number, the
heavier and stiffer the arrow. Fine! But this scrambled
all of our brains even worse because their arbitrary
sizes actually overlapped the arrow deflections.
The Carbon Force 100 has a .500" spine, the 200 has a
.400" spine, the 300 has a .340" spine, and the 400 has
a .300" spine. Try to wrap your noodle around
that! Back to the charts we went.
And just as our grey matter started to congeal from
Carbon Force, Carbon
Express reinvented their generally understandable 30/50,
45/60, 60/75 system (similar to Gold Tip's system but
with the same drawbacks) to a system that's not just
arbitrarily sequential (150, 250, 350), but varies from
shaft to shaft. Their Maxima 250, for example, has
a spine deflection of .404", but the Maxima Hunter
(camo) 250 has a spine deflection of .417". Oh
boy!
It boils down to this. Whether you like Easton
arrows or not, Easton is the big dog in the arrow
market (biggest by far). And Easton's competitors
don't want to be seen as "copycatting" Easton by
following Easton's sizing format. They want to be
unique and develop their own marketing and sizing system
for their products ... even if it ultimately leaves us
all confused. There are well over a dozen popular
carbon arrow manufacturers who sell carbon arrows in the
U.S., and all of them are trying to sing their own tune.
For archery enthusiasts this is both good and bad.
Competition and innovation will continue to keep prices
low and product quality high, but we'll all have to
continue to put our thinking caps on when we shop for
arrows. Because the "universal system" isn't
really so universal.
The only universal system is actual spine
deflection. That's the only
apples-to-apples system that applies to every brand and
model of carbon arrow. As long as the various
carbon arrow manufacturers provide their spine
deflection data (and they test using the industry
standard method), manufacturers can size and market their arrows
by any system they like ... and we can still reference
the proper application to the gold standard Easton
charts. So not to worry. If your favorite
carbon arrow comes in sizes 5000, 6x9, 1080i, and 2XL,
we can always return to the master chart to makes sense
of it.
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