135mm Automatic 3 Gear Hub Belt Drive Internal Gear Hub For Premium E Bikes
| Model: | LG-N7122-3D | Product Type: | Belt Drive Automatic Internal Gear Hub |
| Application: | Belt Drive City E-Bikes / Premium Commuter Platforms | Gear Range: | 166% Total Gear Ratio |
| O.L.D. (Over Locknut Dimension): | 135 Mm | Weight: | 1.64 Kg |
| Shifting Technology: | CentriGear Automatic Mechanical Shifting | Brake Interface: | 6-Bolt Disc Brake |
| Shifting Operation: | Fully Automatic Mechanical Shifting | Drive Compatibility: | Belt Drive System |
| OEM Support: | Belt-Line Review / Cog Matching / Sample Validation | Waterproof Rating: | IPX6 |
| High Light: | 135mm Automatic 3 gear hub,E Bikes 3 gear hub,belt drive internal gear hub OEM |
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The LG-N7122-3D is the belt-drive version of the A03 automatic 3-speed internal gear hub series, developed for city e-bikes and premium commuter bicycles that need a cleaner, quieter and lower-maintenance drivetrain. Its main difference is the 57 mm G1 chainline and matching 9-tooth belt cog with 6.2 mm slot, making it suitable for frame platforms designed around belt drive systems.
Recommended image position: use the dedicated LG-N7122-3D product image after the overview.
Using CentriGear automatic mechanical shifting, the hub changes gears through centrifugal force and planetary gear transmission. Riders can start, cruise and handle moderate city slopes without manual shifting, while the sealed hub body protects the internal transmission mechanism from dust, mud and rainwater.
- Automatic Mechanical Shifting: Shifts between three gears without manual operation.
- Belt Drive Compatibility: Designed for clean, quiet and low-maintenance belt drive e-bike systems.
- 166% Gear Range: Supports smooth starting, efficient cruising and moderate climbing.
- CentriGear Technology: Uses centrifugal force and planetary gears for automatic gear transitions.
- Sealed Hub Structure: Helps protect internal parts from dust, water and road contamination.
- 6-Bolt Disc Brake Support: Compatible with modern disc brake city e-bike platforms.
- 57 mm Chainline: Suitable for specific belt drive frame and drivetrain layouts.
- Low-Maintenance Riding: Reduces exposed drivetrain adjustment and routine service.
This automatic internal gear hub uses a mechanical centrifugal shifting mechanism. As the riding speed increases or decreases, the internal structure responds automatically and shifts between three gear ratios: 1.00, 1.29 and 1.66. This allows the rider to focus on pedaling without selecting gears manually.
The LG-N7122-3D version is especially suitable for belt drive e-bike designs that require a wider chainline layout. Its 57 mm G1 chainline and matching 9-tooth belt cog with 6.2 mm slot make it a practical option for urban frames designed around clean, quiet and low-maintenance drivetrain systems. Because the transmission components are sealed inside the hub shell, the product helps reduce exposure to road dirt and weather conditions, supporting more stable long-term use.
- Automatic 3-speed internal gear hub for belt drive city e-bikes.
- No manual shifter required for regular riding.
- Sealed structure for improved durability and lower maintenance.
- 6-bolt disc brake interface for urban e-bike brake systems.
- 135 mm O.L.D. and 184 mm axle length.
- 57 mm G1 chainline for specific belt drive configurations.
- 9-tooth belt cog with 6.2 mm slot.
- Black finish for integrated premium e-bike appearance.
| Parameter | LG-N7122-3D | LG-N7112-3D |
|---|---|---|
| Product Type | Automatic 3-Speed Belt Drive Version | Automatic 3-Speed Belt Drive Version |
| Product Category | Automatic Gear Hub | Automatic Gear Hub |
| Speed Level | 3 Speed | 3 Speed |
| Total Gear Ratio | 166% | 166% |
| Gear Ratio 1 | 1.00 | 1.00 |
| Gear Ratio 2 | 1.29 | 1.29 |
| Gear Ratio 3 | 1.66 | 1.66 |
| Brake Type | 6-Bolt Disc Brake | 6-Bolt Disc Brake |
| Spoke Size | #13 / #14 | #13 / #14 |
| O.L.D. | 135 mm | 135 mm |
| Axle Length | 184 mm | 184 mm |
| Chainline G1 | 57 mm | 49 mm |
| Chainline G2 | Not Provided | Not Provided |
| Offset | 2.38 mm | 0 mm |
| Axle Length From Hub, Left | 27 mm | 24 mm |
| Axle Length From Hub, Right | 22 mm | 25 mm |
| Thread Size | JIS BC3/8-26 | JIS BC3/8-26 |
| Spoke Hole Diameter | 3.2 mm | 3.2 mm |
| Spoke Hole Number | 36H | 36H |
| Disc Brake Mounting Width | 13 mm | 15.3 mm |
| Color | Black | Black |
| Matching Belt Cog | 9-Tooth Belt Cog, 6.2 mm Slot | Gates CDX9 Belt Cog, 6.5 mm Slot |
| Average Weight | 1.64 kg | 1.64 kg |
| Operating / Storage Temperature | -30–80℃ / -40–85℃ | -30–80℃ / -40–85℃ |
| Waterproof Rating | IPX6 | IPX6 |
| Certifications | ROHS / REACH | ROHS / REACH |
This model is suitable for belt drive city e-bikes, urban commuter bicycles and low-maintenance electric bicycle platforms. It is especially useful for OEM projects that require a clean frame appearance, quiet drivetrain operation and simplified daily riding experience. The automatic shifting structure helps reduce rider operation, while the sealed hub design supports stable use in city commuting, leisure riding and short-distance mobility scenarios.
Before sampling, OEM customers should confirm frame O.L.D., belt-line, belt cog matching, brake interface, axle compatibility and wheel specification. Lofandi can support drawing confirmation, belt-drive matching review, sample preparation and project validation.
Q: Is this model suitable for belt drive e-bikes?
A: Yes. LG-N7122-3D is designed for belt-drive layouts with 57 mm G1 chainline and a matching 9-tooth belt cog with 6.2 mm slot.
Q: What is the main difference from the chain-drive version?
A: The main difference is drivetrain matching. LG-N7122-3D is for belt drive systems, while LG-N7118-3D is for chain drive systems.
Q: What should be confirmed before installation?
A: Confirm frame O.L.D., belt-line, belt cog specification, brake interface, axle compatibility and wheel specification.
Q: Can Lofandi help with belt-drive OEM matching?
A: Yes. Support can include belt-line review, cog matching, drawing confirmation, sample preparation and validation.
Q: Is it suitable for premium commuter projects?
A: Yes. It is suitable for cleaner and quieter belt drive city e-bikes where low routine maintenance and simple operation are important.
Q: How are price, MOQ and delivery confirmed?
A: Price range, MOQ and lead time should be confirmed according to configuration, sample stage and expected order volume.
