Topspin

Cyber Blue 17L (1.20)

Polyester Gauge 17L 1.20 mm In production

Lab measurements for Topspin Cyber Blue 17L (1.20), ranked against all 791 strings in the database. Every figure below is a testing-machine result at a fixed reference tension, not a playtest opinion.

Measured values

Stiffness

185lb/in

lower = softer, kinder on the arm

Tension loss

34%

lower = stays where you strung it

Energy return

87%

higher = livelier, more free power

Spin potential

5.1

higher = more spin off the string bed

Ball bite

0.425COF

higher = grabs the ball harder

String friction

0.083COF

lower = strings slide and snap back

How it ranks against all 791 strings

Stiffness 185 lb/in · 51st pct

Stiffer than 51% of strings tested.

Tension loss 34 % · 55th pct

Sheds more tension than 55% of strings tested.

Energy return 87 % · 41st pct

Livelier than 41% of strings tested.

Spin potential 5.1 · 59th pct

More spin potential than 59% of strings tested.

Ball bite 0.425 COF · 41st pct

Grips the ball harder than 41% of strings tested.

String friction 0.083 COF · 31st pct

More string-on-string friction than 31% of strings tested.

Like Cyber Blue 17L (1.20), but…

Almost nobody looks a string up out of curiosity. You are here because something about your current setup is wrong. Each list below keeps the rest of this string's profile as close as it can while moving decisively on the one thing you picked, so these are swaps rather than merely different strings.

SofterKinder on the arm

FirmerMore control, less launch

More spinBites and snaps back harder

More powerHands more back to the ball

Less powerLower launch, more control

Holds tensionStays where you strung it

What Cyber Blue 17L (1.20) is actually good for

Its standing on each of the site's rankings, out of every measured string in the database. Same arithmetic as the finder, not a separate opinion.

How long it lasts, and how far it stretches

Playable life

~23hours

Estimated from tension loss, on a scale running from 40 hours for the best-holding strings in the database down to 10 for the worst. At four hours a week that is about 6 weeks.

Estimated, not measured. This estimates when the bed goes dead, not when the string snaps. If you break strings before you notice them going dull, you are a breaker, and thickness and material matter far more to you than tension hold does.

Track this in a setup

Elongation under load

0.03.36.69.940 lb51 lb62 lb2.4%2.7%8.8%Pulled toStretch (%)
This stringDatabase median

How far the string stretches when tensioned to a given load. A string that elongates more absorbs more of the impact itself and feels softer; one that barely moves passes more of it on to the frame and the arm.

Measured at every tension and swing speed

The figures at the top of this page come from one test condition: 51 lb at fast swing speed. There are one in total, and all of them are below. Tension moves the bed more than the choice between two similar strings does, so this is the table that actually answers "what will it feel like for me".

Stiffness lb/in lower = softer, kinder on the arm

Strung at Fast swing
51 lb 23.1 kg 185

Tension loss % lower = stays where you strung it

Strung at Fast swing
51 lb 23.1 kg 34

Energy return % higher = livelier, more free power

Strung at Fast swing
51 lb 23.1 kg 87

The highlighted cell is the condition every other figure on this site is quoted at.

What else the machine recorded

Further measurements from the same test, given at the reference condition of 51 lb, fast swing.

Dwell time

35.3ms

How long the ball stays on the string bed. Longer dwell is the physical basis of what players call hold or pocketing.

Bed deflection

32.2mm

How far the string bed moves at impact. More deflection means the bed is doing more of the work of stopping the ball.

Peak force

33lb

The highest force perpendicular to the string bed during impact. The spike the frame and the arm actually receive.

Tension at impact

34.1lb

What the bed is actually pulled to by the time the ball arrives, after it has settled. Always lower than the tension it was strung at.

Loss: settling

3.7lb

Tension lost simply from being strung and left alone, before a ball is hit.

Loss: bedding in

12.9lb

Tension lost while the bed settles over its first impacts.

Loss: impact

0.4lb

Tension lost to the impact itself. Frequently negative, because a bed often gains tension across an impact rather than losing it.

Loss: total

17.0lb

The three losses above added together, in pounds.

Strings that play like this

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

Head to head: Cyber Blue 17L (1.20) vs Poly Tour Pro 17 (1.20) · Cyber Blue 17L (1.20) vs RPM Blast 18 (1.20) · Cyber Blue 17L (1.20) vs RS Lyon 17L (1.20)

More from Topspin

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.

String friction · COF

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

Compare Cyber Blue 17L (1.20) against 791 strings Switching from this? Convert your tension Use it in a hybrid Find it on the map Find the right string for me