Bafang mid-drive e-bike conversion kits, particularly the BBS01B, BBS02B, and BBSHD models, are a favorite among cycling enthusiasts seeking to electrify their rides. Their robust motors, simple installation, and wide compatibility make them a top choice for DIY e-bike builds. To maximize the performance and enjoyment of your Bafang-powered e-bike conversion kit, consider these essential accessories.
The Heart of Your Bafang: Mastering Mid-Drive Components
These essential components work in harmony to deliver a seamless and powerful riding experience, giving you full control over your Bafang-powered mid-drive system.
| Component | Description |
|---|---|
| Gear Shift Sensor | Cuts motor power during gear changes to protect the drivetrain |
| Thumb Throttle | Allows for quick motor engagement with a thumb press |
| Twist Throttle | Provides variable speed control similar to a motorcycle throttle |
| Speed Sensor | Monitors bike speed for appropriate motor assistance |
| USB Programming Cable | Enables customization of motor settings via software |
| Core Components | |
| Mid-Drive Controller | Manages power flow from battery to motor, the “brain” of the e-bike |
| Pedal Assist Sensor (PAS) | Detects pedaling cadence to adjust motor power |
| Hydraulic Brake Sensor | Cuts motor power when hydraulic brakes are applied (optional) |
| Brake Levers | Integrate motor cut-off switches for added safety (optional) |
| Chainring | Affects gearing and performance, available in various sizes for customization |
| Display | Monitors speed, battery level, etc., allows for ride customization |
| Power & Mounting | |
| Battery | Provides energy to power the motor |
| Battery Mount | Securely attaches the battery to the bike frame |
| Torque Arm | Prevents axle spin-out under high torque (recommended for high power) |
| Stabilizer Bar | Keeps the motor securely in place (optional) |
| Chain Guard | Protects clothing and keeps the chain clean |
1. Gear Shift Sensor: The Drivetrain’s Guardian
The gear shift sensor is an electronic device that communicates with the motor controller. When you shift gears, the sensor detects the change in cable tension and momentarily interrupts the motor’s power. This split-second pause allows the gears to engage smoothly without the added stress of the motor’s torque, preserving the lifespan of your chain, cassette, and derailleur.
Installation
- Attach the sensor to your rear derailleur cable.
- Thread the cable through the sensor and secure it with the included clips or ties.
- Connect the sensor to your Bafang mid-drive motor using the appropriate connector.
2. Thumb Throttle: Power at Your Fingertips
The thumb throttle provides an alternative way to control your e-bike’s motor. With a simple press of your thumb, you can engage the motor without pedaling. This is particularly useful for quick acceleration, hill climbing, or when you simply want to give your legs a break.
Installation
- Mount the throttle on your handlebar next to the grip.
- Connect the throttle wire to the matching connector on the Bafang wiring harness.
- Ensure the wire is routed neatly and doesn’t obstruct your bike’s operation.
3. Twist Throttle: The Intuitive Control
The twist throttle replicates the familiar feel of a motorcycle throttle. By rotating the grip, you can seamlessly control the motor’s power and speed. This intuitive design is often favored for longer rides or by those accustomed to motorcycle controls.
Installation
- Secure the twist throttle onto your handlebar using the included clamp.
- Connect the throttle wire to the motor’s wiring harness.
- Verify that the throttle rotates smoothly and the wiring is tidy.
4. Speed Sensor: Your E-Bike’s Pacemaker
The speed sensor is a small device mounted on the rear wheel that measures the bike’s speed. It sends this information to the motor controller, which uses it to regulate the motor’s assistance. This ensures a smooth and consistent power delivery, regardless of your pedaling cadence.
Installation
- Mount the speed sensor on the rear frame near the wheel hub.
- Align the spoke magnet so it passes close to the sensor when the wheel turns.
- Connect the sensor wire to the motor controller.
- Fine-tune the sensor and magnet alignment for accuracy.
5. USB Programming Cable: Customize Your Ride
The USB programming cable is the key to unlocking the full potential of your Bafang mid-drive kit. By connecting the cable to your computer and using Bafang’s software, you can fine-tune a wide range of parameters, including:
- Maximum speed: Set the top assisted speed to comply with local regulations or your personal preferences.
- Pedal assist levels: Adjust the sensitivity and power of the pedal assist system to match your riding style.
- Throttle response: Customize how quickly and forcefully the motor responds to throttle input.
- Current limits: Control the maximum power output of the motor to optimize battery life and performance.
Installation
- Connect the cable to the motor controller and your computer.
- Use Bafang’s software to adjust the settings.
- Save the changes and disconnect the cable.
6. Mid-Drive Controller: The Brain of Your E-Bike
The mid-drive controller is the command center of your Bafang e-bike system. It orchestrates the flow of power from the battery to the motor, responding to your input from the throttle or pedal assist sensor. High-quality controllers like those from Bafang offer efficient power management, customizable settings, and protective features like over-current and over-temperature safeguards.
Upgraded controllers can offer:
- Enhanced power output: For riders seeking more exhilarating acceleration and hill-climbing capabilities.
- Increased efficiency: Leading to extended battery range and more miles per charge.
- Additional features: Like regenerative braking, walk assist, or custom riding modes.
Installation
- Securely mount the controller to your bike frame using the provided brackets.
- Connect the controller to the motor, battery, display, and other components using the color-coded wiring harness.
- Ensure all connections are tight and insulated to protect against the elements.
7. Pedal Assist Sensor: The Effort Amplifier
The pedal assist sensor (PAS) is a small sensor typically located in the bottom bracket area. It detects the rotation of the cranks and your pedaling cadence. This information is relayed to the controller, which then adjusts the motor’s power output to match your effort. The result is a smooth and natural riding experience where the motor feels like an extension of your own legs.
Installation
- Attach the PAS sensor to the bottom bracket shell.
- Secure the magnet ring to the crank arm, ensuring proper alignment with the sensor.
- Connect the PAS sensor to the motor controller using the designated connector.
8. Hydraulic Brake Sensor: Safety First
Hydraulic brake sensors are essential safety devices for e-bikes with hydraulic brakes. When you apply the brakes, the sensor detects the change in pressure within the brake lines and immediately signals the controller to cut off motor power. This ensures instant motor disengagement and prevents any unintended acceleration while braking.
Installation
- Mount the hydraulic brake sensors onto the brake levers.
- Connect the sensor wires to the designated ports on the motor controller.
- Test the brakes and ensure the motor cuts off immediately when the levers are engaged.
9. Brake Levers: Instant Motor Cut-Off
Even if your e-bike doesn’t have hydraulic brakes, you can still achieve instant motor cut-off with specialized brake levers. These levers are equipped with built-in switches that trigger the controller to cut power when the brakes are applied, providing an additional layer of safety.
Installation
- Replace your existing brake levers with the ones included in the kit.
- Connect the brake lever wires to the corresponding connectors on the motor controller.
- Test the brakes and motor cut-off function to ensure proper operation.
10. Chainring: Gear Up for Performance
The chainring is the toothed ring attached to the crank arm that drives the chain. The size of the chainring significantly affects your e-bike’s gearing and performance. Bafang kits typically offer a variety of chainring sizes to suit different riding styles and terrains. Larger chainrings favor higher top speeds, while smaller chainrings excel at hill climbing due to increased torque.
Installation
- Remove the existing chainring from the crank arm.
- Install the new chainring, ensuring it’s securely fastened.
- Adjust the chain tension and alignment as needed.
11. Displays: Your E-Bike’s Dashboard
The display is your e-bike’s information hub, providing crucial data like speed, battery level, power output, pedal assist level, and more. Bafang offers a range of displays, such as the C965, P850C, and DPC-18, each with unique features and interfaces. Many displays also allow you to customize settings and access additional functions like trip tracking and error diagnostics.
Installation
- Attach the display to your handlebar using the provided mount.
- Connect the display to the motor controller using the compatible connector.
- Ensure the display is securely mounted and the wiring is neatly routed and secured.
12. Battery: The Heart of Your E-Bike
The battery is the lifeblood of your electric bike, providing the energy that powers your motor and propels you forward. High-quality lithium-ion batteries are the standard for e-bikes, offering a balance of energy density, lifespan, and weight.
When choosing a battery, consider factors like:
- Capacity: Measured in watt-hours (Wh), this determines your range, or how far you can travel on a single charge.
- Voltage: Most Bafang kits are compatible with either 48V or 52V batteries. Higher voltage can provide more power and torque.
- Size and shape: Batteries come in various form factors to fit different frame styles. Common options include rear rack, downtube, and integrated batteries.
Power & Stability: Essential Mounting & Support For Your Bafang Kit
These components not only keep your battery and motor in place but also protect your newly converted electric bike from the stresses of high power and torque.
1. Battery Mount: Secure the Powerhouse
A battery mount is essential for securely attaching the battery to your bike frame. The type of mount you choose depends on your battery’s size and shape, as well as your personal preference.
Types of battery mounts
- Frame-mounted: Attached to the frame’s downtube or seat tube.
- Rack-mounted: Secured to a rear rack, ideal for larger batteries.
- Integrated: Built into the downtube for a sleek and streamlined look.
2. Torque Arm: Reinforce Your Rear End
The torque arm is a sturdy metal bracket that connects the motor to the bike frame. Its primary function is to counteract the torque generated by the motor, especially during hard acceleration or hill climbing. Without a torque arm, the powerful forces of the motor could cause the rear axle to rotate within the dropouts, leading to misalignment or even damage.
3. Stabilizer Bar: Keep Your Motor in Check
The stabilizer bar is another component that helps to secure the motor and prevent it from rotating within the bottom bracket shell. While not always necessary, it’s especially useful for high-powered Bafang motors or full-suspension bikes where the frame flexes more under load.
4. Chain Guard: Protect Your Pants
A chain guard is a simple but effective accessory that protects your clothing from getting caught in the chainring or chain. It also helps to keep the chain clean and free of debris, which can improve its lifespan and performance. Chain guards come in various styles, from full enclosures to partial covers.
E-Bike Essentials 2.0: Gear Up for Enhanced Performance & Comfort
While the essential accessories we’ve covered form the foundation of a well-functioning Bafang e-bike conversion kit with battery, there are many other upgrades and additions to personalize your ride and enhance your experience:
- Battery Range Extender: Double your range by adding a second e-bike battery to your setup. This is ideal for long-distance commuters or adventurers.
- Upgraded Display: Explore Bafang’s larger, full-color displays with GPS navigation, fitness tracking, and smartphone connectivity.
- Fenders and Racks: Keep yourself and your cargo clean and dry with fenders, and easily carry gear with a sturdy rack.
- Lights: Enhance visibility and safety with powerful front and rear lights.
- Suspension Seatpost: Add comfort to your ride with a suspension seatpost that absorbs bumps and vibrations.
- Phone Mount: Keep your phone within reach for navigation, music, or calls with a secure handlebar mount.
- Throttle Extender: For riders with limited hand mobility, a throttle extender can make it easier to operate the throttle.
Troubleshooting Tips: Smooth Out the Bumps
Even with the best instructions, DIY e-bike conversions can sometimes hit a snag. Here are a few common issues and troubleshooting tips:
- No power: Check all connections, ensure the battery is charged, and verify the display is turned on. If the issue persists, it could be a faulty controller or motor.
- Error codes on the display: Consult the Bafang troubleshooting guide or online forums for specific error code solutions.
- Motor cutting out: This could be due to a loose connection, low battery voltage, or an overheated motor. Double-check wiring, recharge the battery, and allow the motor to cool down.
- Gear shifting issues: Ensure the gear shift sensor is properly aligned and the cable tension is correct.
- Brake sensor problems: Verify the brake sensors are connected and adjusted correctly. The motor should cut off immediately when you apply the brakes.
If you encounter any persistent issues, don’t hesitate to seek help from online communities, your local bike shop, or Bafang’s customer support.
