Isometric 500
Model ISO-500
Where to find it
The frame that changed the shape of badminton: Isometric 500
The head shape every racquet here uses
The Isometric 500 holds a unique place in this database: it is the racquet that introduced the Isometric head to badminton. In 1992, Yonex launched the ISO-500 as the first badminton racquet with a square-cornered Isometric head — a geometry that equalised the length of main and cross strings, enlarging the sweet spot beyond anything an oval frame could achieve. (Yonex had first developed Isometric geometry for tennis racquets in 1980; the badminton application came twelve years later.) Every single racquet in this database — every Carbonex reissue, Armortec, Nanospeed, ArcSaber, Voltric, Nanoray, Duora, Astrox, and Nanoflare — uses a direct descendant of the geometry the ISO-500 introduced to badminton in 1992.
What the ISO-500 was
The frame used a graphite titanium construction with an ultra-fine carbon shaft — a dramatic departure from the oval-headed aluminium and steel frames that had defined professional badminton. The wider body design made the sweet spot forgiving in a way that contemporary players, accustomed to oval frames with tight central sweet spots, found transformative. At $100, the ISO-500 is the cheapest racquet in this database. It is also, by any reasonable measure, the most historically important one on the shelf.
What it means to own one
Authentic ISO-500 specimens are rare finds in any condition — the 1992 launch predates systematic collector documentation, and most examples were played until worn. Yonex's official corporate archive marks the ISO-500 launch as one of the most significant product moments in the company's history. For collectors building a complete Yonex evolution shelf — from pre-Isometric oval heads to the modern Astrox lineup — the ISO-500 is the pivot point. Everything before it is prehistory; everything after is built on what it proved.
Isometric (square-cornered) head shape — distinct from all oval Carbonex predecessors. Graphite titanium frame construction. Ultra-fine carbon shaft. Yonex 'Isometric' branding on shaft or frame. No standard hologram — pre-dates hologram program. Condition grading is critical given age. Japan manufacture. Any oval-headed racquet labeled ISO-500 is incorrect.
The founding artifact of modern racquet geometry. No equivalent exists in the database. Mint examples are museum-grade; played examples retain strong narrative value. Price floor at $100 understates historical significance.
Prices last updated March 2026. All data based on tracked secondary market transactions.