ST Tension Rubber Grommet with Bobbin for Korean Joystick Levers
Give your Korean joystick that brand-new, tournament-ready bounce with the Original Samducksa/Crown ST Tension Rubber Grommet. In Korean arcade levers, the silicone tension grommet performs the exact same function as a metallic spring in a Japanese joystick—it provides directional resistance and snap-back return-to-neutral.
Over time and under heavy usage, all silicone tension rubber grommets wear soft, losing their stiffness and causing your execution to suffer. This original replacement part includes both the high-grade ST series silicone rubber grommet and the matching inner bobbin, restoring your lever’s crispness or allowing you to customize your resistance entirely.
Which Tension Sizing Is Best for You? (Shore Hardness Scale)
The numbers correspond to the silicone’s shore hardness—the lower the number, the lighter and easier the lever is to push. The higher the number, the more force is required to engage, giving you an aggressive return-to-neutral.
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ST-20 (Light Tension – Red Bobbin): Perfect if you are transitioning from Japanese spring-based levers (like the Sanwa JLF) and want a light, wrist-friendly resistance that is easy to engage.
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ST-25 (Light-Medium Tension – White Bobbin):The preferred “sweet spot” for many 2D and 3D players. Offers a slightly heavier throw than a Japanese spring but feels loose enough for fast double-taps.
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ST-30 (Medium Tension – Yellow Bobbin): The factory standard default rating for most standard Crown 300 series and Helpme levers. Highly recommended as a baseline for competitive play.
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ST-35 (Medium-Heavy Tension – Blue Bobbin):] Perfect for those who want a strong snap-back to neutral for 3D movements (like the Korean Backdash) without fatigue.
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ST-45 (Heavy Tension – Black Bobbin): For players who want maximum return force. Excellent for tournament KBDs but requires substantial forearm strength and is not recommended for wrist fatigue issues.
Technical Specifications
| Feature | Specification |
| Brand / Manufacturer | Crown / Samducksa (South Korea) |
| Component Name | ST Tension Rubber Grommet with Bobbin |
| Material | High-grade ST Series Silicone Rubber & Polycarbonate Bobbin |
| Compatibility | Crown 303MJ, 307, 309, New Helpme, Knee Lever, Knee Lever Neo. (Excludes Myoungshin Fanta, Fujin, or Japanese models). |
| Outer Diameter | Standard 300 Series Housing Fitting |
| Interior Fitting | Fits around standard 6mm shafts via the pre-installed inner bobbin |
| Color Coding | Red (20), White (25), Yellow (30), Blue (35), Black (45) |
| Service Life | Natural silicone fatigue rating (Recommend replacement every 6-12 months) |
Step-by-Step Replacement Guide
Changing your Korean lever tension rubber grommet takes roughly 10 minutes:
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Remove the E-Clip & Shaft: Open your arcade stick’s backplate, unhinge the e-clip from the bottom of your lever’s shaft, and pull the shaft up through the top panel to take it out.
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Open the Housing: Unscrew the four corner screws on the bracket underneath the top plate to separate the mounting frame from the plastic housing.
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Swap the Grommet: Lift the old rubber out of the casing[cite: 1.1.8]. Press your new ST Tension Rubber Grommet with pre-installed inner bobbin right in. Make sure the circular guide impressions on the top of the rubber are facing upwards.
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Reassemble: Line up the mounting frame, screw the assembly together, reinsert the shaft, secure the actuator, and pop the bottom e-clip back on. Perform a rapid inputs test to verify smooth movement!
Frequently Asked Questions (FAQ)
1. Does “With Bobbin” mean the plastic piece is included? Yes. Unlike cheap replacement rubbers that require you to dislodge and use your old worn-out inner plastic bobbin, our ST Tension Rubber Grommet comes with a brand-new plastic CWL/SDL shaft bobbin pre-installed inside the center hole. It is ready for direct drop-in install.
2. Can I use these ST grommets on a Myoungshin Fanta? No. This ST/Crown series grommet is specifically designed for Samducksa / Crown 300 Series and Knee levers. If you are tuning a Fanta, Fujin, or Alpha, you will need a Myoungshin-style rubber (Yellow/Blue/Red/Black).
3. When should I replace my grommet? Silicone naturally softens over time from repeated stretching[cite: 1.3.4]. If your Korean lever begins to feel loose, drops its snap-back speed to neutral, or wobbles in the center, it is time to drop in a fresh ST gromme.
4. Where can I buy a genuine Korean lever tension rubber grommet in India? You can purchase original South Korean Samducksa tuning components directly from Game Store India with rapid domestic shipping, secure packaging, and Cash on Delivery (COD)—bypassing high overseas shipping markup and customs delays.
