Automatic 3-Speed Internal Gear Hub For Urban Utility E-Bikes

The A03 Automatic 3-Speed Internal Gear Hub is designed for urban utility e-bikes, commuter bicycles and OEM city mobility projects that need automatic gear shifting without electronic control. It gives vehicle brands a simple, sealed and maintenance-free internal gear hub solution for daily riding, short-distance utility use and low-maintenance drivetrain planning.

A03 uses CentriGear mechanical shifting technology. Based on centrifugal-force triggering and planetary gear operation, the hub automatically changes between three gear ratios as riding conditions change. Riders do not need to operate a manual shifter, making the product suitable for city e-bikes where easy starts, stable cruising and simplified operation are more important than complex external shifting systems.

The series includes two model directions: LG-N7118-3D for chain drive projects and LG-N7122-3D for belt drive projects. Both versions use 6-bolt disc brake matching, 135 mm O.L.D., 166% total gear range, IPX6 waterproof protection and RoHS / REACH certification. For OEM teams, A03 should be reviewed together with frame spacing, brake layout, chainline or belt-line target, wheel build and expected riding conditions before sampling.

• Mechanical Automatic 3-Speed Shifting: No electronic controller, CAN, Bluetooth or manual shifter required for gear change.
• CentriGear Shifting Technology: Uses centrifugal-force triggering and planetary gear operation to shift automatically.
• 166% Total Gear Range: Covers common urban riding stages including starting, cruising and higher-speed city riding.
• Chain And Belt Drive Options: LG-N7118-3D supports chain drive projects, while LG-N7122-3D supports belt drive projects.
• 6-Bolt Disc Brake Matching: Source-backed brake interface for city e-bike and commuter OEM applications.
• 135 mm O.L.D. Rear Hub Layout: Suitable for OEM projects that require a compact automatic internal gear hub direction.
• Maintenance-Free Sealed Design: Helps reduce exposed shifting parts and routine drivetrain adjustment.
• IPX6 And RoHS / REACH: Provides a clear baseline for waterproof and compliance review.

A03 is a mechanical automatic internal gear hub. Its shifting logic is based on CentriGear technology, where centrifugal force works with a planetary gear mechanism to change gear ratios automatically as riding speed changes.

At lower riding speeds, the hub supports easier starting. As the bicycle accelerates, the internal mechanism shifts into higher ratios for more efficient cruising. Because the shift process is mechanical, A03 does not require electronic control, CAN communication, Bluetooth operation or a handlebar shifter.

This makes A03 suitable for OEM projects that want automatic shifting with fewer exposed drivetrain components, especially for urban e-bikes, commuter bicycles and utility city mobility platforms.

A03 is suitable for:

• Urban utility e-bikes
• City commuter bicycles
• Low-maintenance city mobility platforms
• OEM e-bike projects using automatic internal gear hubs
• Chain drive or belt drive rear hub drivetrain designs
• City vehicles where simplified rider operation is important

For special vehicle structures or riding environments outside regular urban utility use, project matching should be confirmed separately according to frame design, wheel build, brake layout and expected operating conditions.

Before sampling, OEM customers should confirm rear frame drawing, 135 mm O.L.D., brake layout, wheel size, spoke specification, chainline or belt-line target, cog matching, cable-free drivetrain layout and expected riding scenario.

LG-N7118-3D is recommended for chain drive projects. LG-N7122-3D is recommended for belt drive projects. Final model selection should be confirmed according to frame structure, drivetrain design and wheel build requirements.