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Gosen

AK Pro Spin 15L (1.38)

Nylon Gauge 15L 1.30 mm In production

Lab measurements for Gosen AK Pro Spin 15L (1.38), ranked against all 789 strings in the database. Every figure below is a testing-machine result at a fixed reference tension, not a playtest opinion.

Measured values

Stiffness

169lb/in

lower = softer, kinder on the arm

Tension loss

12%

lower = stays where you strung it

Energy return

92%

higher = livelier, more free power

Spin potential

6.0

higher = more spin off the string bed

Ball bite

0.446COF

higher = grabs the ball harder

Snapback

0.074COF

lower = strings slide and snap back

How it ranks against all 789 strings

Stiffness 169 lb/in · 37th pct

Stiffer than 37% of strings tested.

Tension loss 12 % · 1st pct

Sheds more tension than 1% of strings tested — outstanding tension maintenance.

Energy return 92 % · 74th pct

Livelier than 74% of strings tested.

Spin potential 6.0 · 79th pct

More spin potential than 79% of strings tested.

Ball bite 0.446 COF · 53rd pct

Grips the ball harder than 53% of strings tested.

Snapback 0.074 COF · 11th pct

More string-on-string friction than 11% of strings tested.

Strings that play like this

Closest matches across stiffness, tension loss, energy return and spin potential.

Tourna Synthetic Gut Armor 16 97% match Babolat Synthetic Gut 16 (1.30) 95% match Babolat Synthetic Gut 17 (1.25) 94% match Gamma Synthetic Gut 18 (1.18) 94% match Wilson NXT Duramax 16 (1.32) 93% match Gamma TNT2 18 (1.17) 93% match

More from Gosen

What these numbers mean

Stiffness · lb/in

How much the string bed resists deflection. Higher plays firmer and more controlled; lower plays softer and easier on the arm.

Tension loss · %

Share of the reference tension the string sheds under a fixed test protocol. Lower means the bed stays where you strung it for longer.

Energy return · %

Share of impact energy handed back to the ball. Higher plays livelier and more powerful.

Spin potential

Ball friction divided by string-on-string friction. Higher means better bite with a cleaner snapback, so more spin.

Ball bite · COF

String-on-ball friction. Higher grabs the ball harder through the brush.

Snapback · COF

String-on-string friction. Lower lets the mains slide and snap back into place after impact.

Compare AK Pro Spin 15L (1.38) against 789 strings Find the right string for me