Butterfly Sriver FX vs Nittaku Fastarc S-1: Which Should You Buy?

UltraSpin comparison · 2026-06-12 · rubber

Butterfly Sriver FXNittaku Fastarc S-1
Our rating7.8/107.9/10
best_sidebothforehand or backhand
controlhigh70
speedmedium97
spinmedium-high96
sponge_hardnesssoft35 degrees
typehigh-tension inverted (soft)inverted
weight_uncut_g62around 41-43g

We may earn a commission from links on this page. Learn more.

Sriver FX (7.8) is the trusted control classic. Nittaku Fastarc S-1 (7.9 rating) is the lightweight upgrade: genuine tensor speed without excessive stiffness, excellent blocking, grippy feedback, and extremely light (around 41g uncut). S-1’s spin lags behind competitive tensors and peers, trading pure spin for accessibility and pace.

Sriver FX for beginners and blockers. Fastarc S-1 for intermediate all-round attackers wanting speed and lightweight swing without peak spin.

FAQ

Why is S-1 so much lighter?

Design priority. S-1 targets accessibility and ease of swing; Sriver FX’s weight comes from its forgiving sponge.

Is S-1 easier to learn than Sriver FX?

Not easier, but different. Sriver FX is softer and safer; S-1 is more lively but requires developed technique.

Can S-1 spin like Sriver FX?

S-1 spins adequately but not as easily. Sriver FX’s soft topsheet is more forgiving for spin strokes.

Best blade pairing for S-1?

All-wood and moderate off-blades pair well. The lightweight nature suits any blade speed.

Which is more durable?

Both solid. Sriver FX is a classic; S-1 reports strong durability under training.