String comparison
RPM Blast vs Hyperion
Babolat RPM Blast against Signum Pro Hyperion: ratings, specs and which one fits your junior.
The short answer
Both are polyester strings. RPM Blast leads on spin and control. Hyperion leads on power, comfort and tension hold. For a junior with arm concerns, Hyperion is the safer choice. Hyperion costs less per set.
Ratings
Power
Spin
Control
Comfort
Durability
Tension hold
Ratings are on a 1–10 scale. The higher score is in bold when they differ.
Pick RPM Blast if…
- You want more spin (10 vs 7 out of 10)
- You want more control (9 vs 7 out of 10)
- Best for: heavy topspin players
- Best for: advanced juniors with fast, full swings
- Best for: players who generate their own power
Pick Hyperion if…
- You want more power (8 vs 6 out of 10)
- You want more comfort (6 vs 5 out of 10)
- You want more tension hold (8 vs 5 out of 10)
- Arm comfort comes first (arm friendliness 3/5 vs 2/5)
- Your player is younger (recommended from age 12 vs 14)
- You want to spend less (from $10 vs $20 a set)
- Best for: players wanting power from poly
- Best for: hard hitters seeking directional control
- Best for: those frustrated by dead-feeling polys
Specs side by side
| Spec | RPM Blast | Hyperion |
|---|---|---|
| Type | Polyester | Polyester |
| Construction | Octagonal high-density co-polyester monofilament | Round co-polyester monofilament with optimized molecular structure |
| Gauges | 16, 17, 18 | 16, 17, 18 |
| Stiffness | Medium high | Medium |
| Set price | $20–21 | $10–13 |
| Reel price | $130–150 | $130–150 |
| Arm friendliness | 2/5 · Low | 3/5 · Moderate |
| Cost to maintain | 3/5 | 4/5 |
| Recommended from | Age 14 | Age 12 |
| Levels | Advanced, Elite | Intermediate, Advanced, Elite |
| Play styles | Baseliner, Big hitter | Baseliner, All court, Big hitter |
| Junior tension | 46-50 lbs for juniors. String lower to unlock spin potential. Loses tension quickly so some players string 2-3 lbs higher. | 48-52 lbs for juniors. String 10% lower than normal - high tension maintenance. |
RPM Blast in short
Babolat RPM Blast is one of the most iconic co-polyester strings ever made. When Rafael Nadal showed up at the 2010 Australian Open with this octagonally shaped co-poly, it changed the game. The octagonal structure with high-density co-polyester adds phenomenal rotation to the ball. The slick surface enables the strings to snap back with vicious force, resulting in extra RPMs. One of the most popular co-polys of all time, this firm and durable string is perfect for big hitters looking to load the ball with pace and spin.
Hyperion in short
Signum Pro Hyperion is part of the Blackline power series, featuring an optimized molecular structure for incredible power and touch rarely found in co-polyesters. The greater elasticity of the co-polyester structure provides enhanced comfort and power while maintaining directional control for hard hitters. Signum Pro suggests stringing 10% lower than normal due to the exceptional tension maintenance characteristics.
RPM Blast vs Hyperion: quick answers
Which has more spin, RPM Blast or Hyperion?
Babolat RPM Blast, with a spin rating of 10/10 against 7/10.
Which is more arm-friendly for a junior?
Signum Pro Hyperion scores 3/5 for arm friendliness, against 2/5 for RPM Blast. It is recommended from age 12.
Which lasts longer?
They tie on durability (7/10). Tension maintenance: RPM Blast 5/10, Hyperion 8/10.
Which is cheaper?
RPM Blast costs about $20–21 a set and Hyperion about $10–13, at typical retail.
The short answer and the "pick if" lists are generated from our ratings and junior data only. Data verified 2025-01 (RPM Blast) and 2025-01 (Hyperion).