Product Description
Automatic 3-Speed Internal Gear Hub | Official Product Description
Product Overview
The Threaded Sprocket Automatic 3-Speed Gear Hub is designed for city e-bikes, commuter bicycles and OEM urban bike projects that need automatic shifting with practical rear drivetrain matching. Based on LG-N7118-3D, this version focuses on threaded sprocket matching instead of positioning the product as a generic chain-drive or belt-drive hub.
With CentriGear automatic mechanical shifting, the hub changes gears according to riding speed through centrifugal force and planetary gear transmission. Riders do not need to operate a handlebar shifter during daily city riding, which helps make starts, cruising and moderate urban climbing easier to manage.
For OEM bicycle brands, LG-N7118-3D provides a sealed rear hub solution with 6-bolt disc brake compatibility and a black finish for modern city e-bike platforms. The threaded sprocket configuration should be matched with the frame, drivetrain layout and rear hub installation requirements before sampling.
Key Features
Threaded Sprocket Matching: Designed around the LG-N7118-3D threaded sprocket / threaded buckle configuration.
Automatic 3-Speed Shifting: Supports automatic gear changes without manual shifting during regular riding.
CentriGear Technology: Uses centrifugal force and planetary gears for mechanical automatic shifting.
City E-Bike Application: Suitable for city e-bikes, commuter bicycles and OEM urban mobility projects.
Sealed Internal Gear Structure: Helps protect the transmission mechanism from dust, mud and rainwater.
6-Bolt Disc Brake Compatibility: Matches modern city e-bike brake system requirements.
Compact Rear Hub Integration: Keeps the drivetrain cleaner than exposed shifting systems.
IPX6 Waterproof Rating: Suitable for regular outdoor riding and urban commuting conditions.
Technical Advantages / How It Works
LG-N7118-3D uses a CentriGear mechanical automatic shifting system built inside the rear hub. As riding speed changes, the internal centrifugal mechanism works with the planetary gear structure to shift between three gear ratios automatically.
The main differentiation of this model is its threaded sprocket matching direction. This makes the product useful for OEM projects that need automatic shifting while keeping a practical rear drivetrain structure. Because the shifting mechanism is sealed inside the hub shell, the rear drivetrain can stay cleaner and less exposed to daily road contamination.
Before integration, OEM teams should confirm frame O.L.D., threaded sprocket matching, drivetrain line, brake interface, spoke specification, axle layout and target riding scenario.
Technical Parameters
| Parameter | LG-N7118-3D |
|---|
| Product Type | Automatic 3-Speed Threaded Sprocket Version |
| Product Category | Automatic Gear Hub |
| Speed Level | 3 Speed |
| Total Gear Ratio | 166% |
| Gear Ratio 1 | 1.00 |
| Gear Ratio 2 | 1.29 |
| Gear Ratio 3 | 1.66 |
| Brake Type | 6-Bolt Disc Brake |
| Spoke Size | #13 / #14 |
| O.L.D. | 135 mm |
| Axle Length | 184 mm |
| Chainline G1 | 49 mm |
| Chainline G2 | 43.4 mm |
| Offset | 2.4 mm |
| Axle Length From Hub, Left | 27 mm |
| Axle Length From Hub, Right | 22 mm |
| Thread Size | JIS BC3/8-26 |
| Spoke Hole Diameter | 3.2 mm |
| Spoke Hole Number | 36H |
| Disc Brake Mounting Width | 13 mm |
| Color | Black |
| Matching Belt Cog | Not Provided |
| Average Weight | 1.64 kg |
| Operating / Storage Temperature | -30–80℃ / -40–85℃ |
| Waterproof Rating | IPX6 |
| Certifications | ROHS / REACH |
Applications
LG-N7118-3D is suitable for city e-bikes, commuter bicycles and OEM urban bike platforms that require automatic shifting, sealed drivetrain protection and 6-bolt disc brake compatibility.
It is especially useful for projects that need a practical threaded sprocket rear hub configuration while keeping rider operation simple and reducing exposed shifting components.
OEM / Service Support
Before sampling or production, confirm frame O.L.D., threaded sprocket matching, drivetrain line, brake interface, spoke specification, axle layout, wheel build and target riding conditions.
FAQ
Q: Is this model suitable for chain drive e-bikes?
A: LG-N7118-3D uses a threaded sprocket / threaded buckle matching direction, making it different from the belt cog versions in the A03 series.
Q: Does the rider need to shift manually?
A: No. The hub uses CentriGear mechanical automatic shifting based on centrifugal force and planetary gears.
Q: What should OEM customers provide before sampling?
A: Please provide frame drawing, O.L.D., chainline, brake interface, spoke specification, axle layout and target riding conditions.
Q: Can Lofandi support OEM drivetrain matching?
A: Yes. Support can include product selection, drawing review, chainline confirmation, sample preparation and project validation.
Q: How is product quality checked before delivery?
A: Quality checks may include functional inspection, gear shifting verification, waterproof review, installation matching and project-specific validation.
Q: How are price, MOQ and lead time confirmed?
A: They should be confirmed according to order volume, project configuration, sample requirements and delivery plan.
