Head to head
Kirschbaum Helix 17 vs Signum Pro Poly-Plasma Pure 16L
They split the measurements 3–3. The widest gap is ball bite, where Poly-Plasma Pure 16L is 32 percentile points ahead. Every figure is a testing-machine result at a fixed reference tension.
Measured, side by side
Bars are percentile against all 788 strings, and the marked side is the one that measures better, which is not always the one you want. A firmer bed is worse for your elbow and better for your control, and no measurement knows which of those you came for.
Which one wins, by problem
Each string's standing on the site's rankings, out of every measured string in the database. This is where a comparison stops being arithmetic and starts being a decision.
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Helix 17258th
Poly-Plasma Pure 16L203rd
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Helix 17658th
Poly-Plasma Pure 16L731st
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Helix 17134th
Poly-Plasma Pure 16L35th
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Helix 17647th
Poly-Plasma Pure 16L721st
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Helix 17578th
Poly-Plasma Pure 16L538th
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Helix 17208th
Poly-Plasma Pure 16L111th
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Helix 17652nd
Poly-Plasma Pure 16L719th
Swapping between them: what tension?
Bed stiffness is published at one reference tension, so the only honest conversion is to scale it. These are starting points from 52 lb, not prescriptions. The calculator takes your own tension.
Coming from Helix 17 at 52 lb
String Poly-Plasma Pure 16L at 46.4 lb 21.0 kg
Coming from Poly-Plasma Pure 16L at 52 lb
String Helix 17 at 56.9 lb 25.8 kg
Hybrid: what if you used both?
Estimated, not measured. No hybrid combination has been tested as a bed. These figures are the two strings' own lab measurements weighted by how much of the bed each one actually is. Treat them as a guide to which way a pairing moves, never as lab data.
Helix 17 mains / Poly-Plasma Pure 16L crosses
Poly-Plasma Pure 16L mains / Helix 17 crosses
Which goes dead first?
Estimated from tension loss, which is the only thing the database measures about ageing. This is when the bed stops playing the way you strung it, not when the string breaks.
Helix 17
~18 hours of play
Poly-Plasma Pure 16L
~20 hours of play
Both strings in full
| String | Gauge | Price | Stiff lb/in | Loss % | Power % | Spin | Bite COF | Friction COF |
|---|---|---|---|---|---|---|---|---|
| Kirschbaum Helix 17 Polyester | 17 | find | 209 | 44 | 86 | 5.4 | 0.414 | 0.076 |
| Signum Pro Poly-Plasma Pure 16L Polyester | 16L | find | 221 | 41 | 86 | 5.6 | 0.467 | 0.083 |
Add a third string Helix 17 in full Poly-Plasma Pure 16L in full