SPIDER Automation | 420 29T E-Bike Drive Sprocket | Four-Hole Mounting for Gearless Freewheel Systems
The SPIDER Automation 420 29T E-Bike Drive Sprocket is a chain-driven transmission component designed for compatible electric bicycle and electric vehicle drivetrain assemblies. Its 29-tooth profile and 12.7mm tooth pitch are intended for use with a matching 420 chain, allowing rotational power to be transferred through the chain-drive system.
The sprocket uses a four-hole mounting arrangement designed for a compatible gearless freewheel interface with a 95mm outer diameter. The mounting-hole spacing, central opening and hole diameter are important when selecting this sprocket for an existing drivetrain or custom electric vehicle conversion.
Technical Features & Functional Characteristics
- 29-Tooth Sprocket Profile: Provides a 29T configuration for the driven side of a compatible chain transmission.
- 420 Chain Pitch: Designed around a 12.7mm tooth pitch to match the corresponding 420 chain geometry.
- Four-Hole Mounting Pattern: Uses four mounting holes arranged around the central opening.
- Gearless Freewheel Compatibility: Designed for a compatible four-hole gearless freewheel with a 95mm outer diameter.
- Defined Hole Spacing: The adjacent-hole and diagonal-hole centre distances provide reference dimensions for mounting alignment.
- Chain Power Transmission: Transfers rotational movement through the engaged chain to the connected drivetrain.
420 Chain Drive & Sprocket Function
A chain sprocket transfers rotational movement through engagement between its teeth and the chain rollers. The 29T tooth count determines the sprocket’s contribution to the overall drivetrain ratio when paired with another sprocket.
For proper operation, the chain pitch and tooth profile must match. The final speed and torque characteristics depend on the complete sprocket combination, motor speed, wheel size, controller configuration and operating load. A sprocket alone does not establish a particular vehicle speed.
Mounting Configuration
This sprocket features four mounting holes and is intended for a compatible gearless freewheel interface. Its central opening is designed around a freewheel having a 95mm outer diameter. The mounting-hole diameter and centre spacing should be matched with the mating component before assembly.
Applications
The sprocket is intended for electric mobility and chain-driven transmission projects that use a matching 420 chain and compatible four-hole gearless freewheel mounting arrangement.
- E-Bike Drivetrain Assemblies: For compatible electric bicycle transmission systems using a 420 chain.
- Electric Bicycle Conversion Projects: Suitable for conversion builds designed around the matching chain and freewheel mounting pattern.
- Gearless Freewheel Systems: For compatible four-hole gearless freewheel assemblies with the specified mounting interface.
- Electric Tricycle Drivetrains: Can be used in compatible chain-driven electric tricycle transmission arrangements.
- Custom Electric Vehicles: For projects using a matching 420 chain and four-hole sprocket mounting arrangement.
- Motor-Driven Chain Transmissions: Transfers rotational power through a compatible chain-drive assembly.
- Drivetrain Repair & Replacement: Replacement option for a worn or damaged sprocket with matching dimensions.
- Electric Mobility Workshops: Useful for servicing and assembling compatible chain-driven electric vehicle systems.
Package Includes
- 1 × 420 29T E-Bike Drive Sprocket
Product Specifications
| Parameter | Specification |
|---|---|
| Product Type | E-Bike Drive Sprocket |
| Chain Designation | 420 Chain |
| Number of Teeth | 29T |
| Chain / Tooth Pitch | 12.7mm |
| Outer Diameter | 122mm |
| Inner Diameter | 64mm |
| Thickness | 5mm |
| Number of Mounting Holes | 4 |
| Mounting Hole Diameter | 8mm |
| Adjacent-Hole Centre Distance | 57mm |
| Diagonal-Hole Centre Distance | 81mm |
| Compatible Freewheel Interface | Four-hole gearless freewheel with 95mm outer diameter |
| Product Weight | 270g |
| Package Quantity | 1 Piece |
Installation & Operating Recommendations
Correct chain selection, mounting alignment and secure fastening are essential for reliable sprocket operation. Consider the following points during installation:
- Match the Chain: Use a 420 chain with matching pitch and roller geometry to ensure proper engagement with the sprocket teeth.
- Confirm Freewheel Compatibility: Check that the mating gearless freewheel has the corresponding four-hole mounting arrangement and 95mm outer diameter.
- Verify Hole Alignment: Match the 8mm mounting holes and the adjacent and diagonal centre distances with the mating component.
- Use Suitable Fasteners: Select bolts appropriate for the mounting interface and secure the sprocket evenly.
- Maintain Sprocket Alignment: Keep the sprocket aligned with the mating chain sprocket to reduce side loading and uneven wear.
- Set Correct Chain Tension: Avoid excessive slack or over-tightening, both of which can affect drivetrain operation and component life.
- Inspect Before Riding: Rotate the drivetrain manually to check chain movement, tooth engagement and mounting clearance before applying motor power.
- Review the Complete Gear Ratio: Select the mating sprocket according to the required drivetrain ratio and the motor’s operating characteristics.
