UTILITY · 01 / 02

Arrow Spine
Selector.

Stiffness governs flight. An arrow under-spined for your bow will fishtail; over-spined will porpoise. This tool maps your bow setup against our shaft library and returns the spine you should be shooting — no guesswork, no chart-scrolling.

INTERACTIVE CALCULATOR

Find your
Goshawk spine.

// PLUGIN · ARROW SPINE SELECTOR · V1.1.0

Arrow Spine Selector

Enter your bow specs below to find your perfect African Reaper shaft.

20 lbs60 lbs100 lbs
22"28"34"
22"29"36"

Typically draw length + 0.5–2 inches. Measure nock groove to end of shaft.

60 gr155 gr250 gr
Recommended Spine
–
Effective Weight –
Also Consider –
Stiffness –
Shop Recommended Shafts
WHY IT MATTERS

Stiffness is the
silent variable.

UNDER-SPINED · 01

Too weak

Shaft flexes excessively at release. Arrow paradoxes outside the riser, fishtails on launch and loses energy fighting itself in flight. Groups open up at distance.

MATCHED · 02

Tuned

Shaft flexes just enough to clear the riser then recovers cleanly. Bare-shaft and fletched impacts converge. Maximum energy transfer to target — accuracy and penetration both peak.

OVER-SPINED · 03

Too stiff

Shaft refuses to flex around the riser. Porpoises vertically, kicks off the rest, and bleeds energy. Tunable only with band-aids: shorter shafts, heavier points, weaker spines.

QUICK LOOKUP

Spine deflection
chart.

Draw Weight 26″27″28″29″30″31″32″
40–45 lb 500 500 500 400 400 400 350
45–50 lb 500 500 400 400 400 350 350
50–55 lb 500 400 400 400 350 350 300
55–60 lb 400 400 400 350 350 300 300
60–65 lb 400 400 350 350 300 300 300
65–70 lb 400 350 350 300 300 300 250
70–75 lb 350 350 300 300 300 250 250
75–80 lb 350 300 300 300 250 250 200
80–85 lb 300 300 300 250 250 200 200
Draw Weight 26″27″28″29″30″31″32″
40–45 lb 500 500 400 400 400 350 350
45–50 lb 500 400 400 400 350 350 300
50–55 lb 400 400 400 350 350 300 300
55–60 lb 400 400 350 350 300 300 300
60–65 lb 400 350 350 300 300 300 250
65–70 lb 350 350 300 300 300 250 250
70–75 lb 350 300 300 300 250 250 200
75–80 lb 300 300 300 250 250 200 200
80–85 lb 300 300 250 250 200 200 200
250 · 300 · 350 · 400 — AVAILABLE IN GOSHAWK 500 — OUTSIDE GOSHAWK RANGE · CONTACT US 200 — BELOW GOSHAWK RANGE · LIGHTER BOW RECOMMENDED

// BASIS · COMPOUND BOW · MECHANICAL RELEASE · STANDARD DRAW. MOVE ONE SPINE STIFFER FOR FINGER RELEASE OR BRACE HEIGHT BELOW 6½″.