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Sonic Pro 17

Polyester Gauge 17 1.26 mm In production

Lab measurements for Head Sonic Pro 17, 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

165lb/in

lower = softer, kinder on the arm

Tension loss

55%

lower = stays where you strung it

Energy return

84%

higher = livelier, more free power

Spin potential

3.9

higher = more spin off the string bed

Ball bite

0.342COF

higher = grabs the ball harder

Snapback

0.087COF

lower = strings slide and snap back

How it ranks against all 789 strings

Stiffness 165 lb/in · 32nd pct

Stiffer than 32% of strings tested.

Tension loss 55 % · 94th pct

Sheds more tension than 94% of strings tested — goes dead fast, expect frequent restringing.

Energy return 84 % · 13th pct

Livelier than 13% of strings tested.

Spin potential 3.9 · 27th pct

More spin potential than 27% of strings tested.

Ball bite 0.342 COF · 2nd pct

Grips the ball harder than 2% of strings tested — slick against the ball.

Snapback 0.087 COF · 39th pct

More string-on-string friction than 39% of strings tested.

Strings that play like this

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

Weiss Cannon Silverstring 120 95% match Topspin Cyber Flash 17 94% match Polyfibre TCS 16L 94% match Head Sonic Pro 16 94% match Poly Star Classic 17 (1.20) 94% match Poly Star Energy 17 (1.20) 93% match

More from Head

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 Sonic Pro 17 against 789 strings Find the right string for me