Bafang M400 motor integrated into an electric mountain bike (eMTB) frame

Bafang M400 Review: The Smooth 250W Mid-Drive Motor For Everyday Challenges

The Bafang M400 Mid-Drive Motor, or simply the “Max Drive”, is a game-changer for riders seeking a perfect balance of power, efficiency, and value. Whether you’re conquering your daily commute, exploring scenic trails, or tackling the steepest climbs, the M400 is your ticket to electrifying your ride. Let’s unravel the secrets behind this popular motor, exploring its features, performance capabilities, and the potential to personalize it for your unique riding style.

Key Features & Specifications: Your Bafang M400 At A Glance

Let’s get down to brass tacks – what makes the Bafang M400 tick? This quick overview of its specs will show you what this motor can offer for your e-bike adventures.

Feature Specification
Rated Power 250W
Maximum Torque 80 Nm
Voltage Range 36V / 43V / 48V
Operating Temperature -18°C to 60°C
Storage Temperature -30°C to 70°C
Water Resistance IP65
Compatibility City and trekking eBikes
Display Unit DP C07
Weight Approximately 3.9 kg
Maximum Speed Support Up to 25 km/h (regulated for legal compliance)
Battery Options 340Wh to 490Wh Lithium-ion
Charging Time Approximately 4.5 hours (with a 2A charger)
Communication Protocol UART or CanBus
Assistance Levels 5 levels
Walk Assist Yes

The Heart of Your E-Bike: Design & Technology

Close-up of the Bafang M400 motor installed on an e-bike

More than just a motor, the M400 is a marvel of engineering designed to integrate seamlessly with your e-bike. Let’s take a closer look at the sleek design and smart technology that make this motor a cut above the rest.

  • Integrated Design for Seamless Performance

Unlike its predecessors that clung to the bottom bracket, the M400 elegantly integrates into your e-bike’s frame. This not only gives your ride a sleek, clean look but also boosts durability and stability, ensuring your motor is protected from the elements and the bumps along the way. The seamless integration also enhances weight distribution and improves overall bike handling.

  • Intelligent Sensors for a Responsive Ride

The M400 is equipped with a trio of sensors – monitoring pedal speed (cadence), pedal torque, and rear wheel speed – working together to provide you with a smooth and intuitive power delivery. No more jerky starts or unexpected surges – just a natural feeling of assistance that adapts to your every move, especially crucial during rapid acceleration or hill climbs.

Note on Shift Sensing: While the M400’s sensors are highly responsive, it’s worth noting that the motor lacks shift sensing. This means you’ll need to be mindful when shifting gears, especially on challenging terrains, to avoid any potential gear mashing.

Bafang M400 Performance: Putting the 250W mid-drive motor to the Test

Detailed view of the Bafang M400 motor's internal components

Hold on tight – it’s time to unleash the full potential of the M400! We’ve put this motor through its paces on city streets, rugged trails, and challenging climbs. Get ready to discover its true capabilities.

  • Power and Torque

The M400 boasts a rated power of 250W and an impressive 80 Nm of torque, conquering various terrains with confidence. From cruising city streets to conquering steep hills, the motor delivers consistent power without breaking a sweat (or overheating!).

  • Speed and Assist Levels

The Bafang M400 respects the European e-bike speed limit of 25 km/h, ensuring you stay on the right side of the law. But don’t let that fool you – with the right gear shifting, this motor has been known to reach 26+ mph while maintaining a whisper-quiet operation. Five levels of pedal assist let you tailor the experience to your preference and the demands of the terrain.

  • Battery and Range

A variety of battery options (340Wh to 490Wh) cater to different riding needs, offering a potential range of 40 km to 100 km on a single charge. Recharge time is around 4.5 hours with a standard 2A charger, making the M400 a convenient choice for daily commutes.

Bafang M400 250W mid-drive motor

Bafang M400 250W


The M400’s All-Terrain Prowess: From city streets to mountain summits

Whether you’re a city slicker, a trail enthusiast, or a hill-climbing hero, the Bafang M400 has the versatility to conquer any terrain you throw at it. Let’s explore how this motor excels in different environments.

  • City Slicker

The M400 thrives in urban environments, providing smooth acceleration and intuitive assistance for navigating traffic and tackling those daily commutes with ease. The torque sensor’s sensitivity ensures quick adaptation to changing traffic conditions, providing a seamless ride experience.

  • Trailblazer (Light Off-Road)

While designed primarily for city life, the M400 holds its own on light off-road trails. Its rugged build and ample torque make it a capable companion on gravel paths and moderate dirt tracks.

  • Hill Climber

Here’s where the M400’s torque truly shines. This motor empowers you to conquer steep inclines without breaking a sweat, making those once-dreaded hills a breeze to climb. Users have reported that the motor maintains a steady performance during prolonged climbs, though it’s essential to manage gears properly to avoid gear mashing.

User Interface & Controls: Your M400 Command Center

Bafang M400 motor with its accompanying display unit Bafang DPC07

Taking control of your e-bike should be effortless and intuitive. The M400’s user interface and controls make it easy to monitor your ride and adjust your settings on the fly. Let’s see how it all works.

  • Intuitive Displays

The Bafang M400 is compatible with various Bafang displays (DPC07, DPC10, DPE12, etc.) that offer clear readouts of speed, battery life, assist level, and more. These displays are easy to navigate, feature backlighting for low-light conditions, and can be customized to your liking.

  • Ergonomic Control Unit

The handlebar-mounted control unit lets you effortlessly switch assist levels or turn the system on and off without ever taking your hands off the bars.

Beyond the Basics: Installation, Maintenance & Beyond

The Bafang M400 isn’t just about performance – it’s about making your e-bike ownership a breeze. From hassle-free installation to reliable operation and beyond, let’s explore what makes this motor a joy to own.

  • Versatile Installation

The Bafang M400’s compact design and adaptable mounting system suit a variety of e-bike frames, from city bikes to trekking bikes and some mountain bikes. Basic mechanical skills are all you need for installation, with detailed instructions provided for a smooth setup.

  • Reliability and Support

Bafang is known for building motors that go the distance, and the M400 upholds that reputation. Routine maintenance is simple, and Bafang’s solid warranty and customer support provide peace of mind for your investment.

Bafang M400 250W mid-drive motor

Bafang M400 250W


Bafang Family Comparison: BBS01B (M215), M400, M410 & M420 Mid-Drive Motors

Not sure if the Bafang M400 is the perfect fit for you. Let’s compare it to its Bafang siblings and see how they stack up in terms of features, performance, and ideal use cases.

Feature BBS01B (M215) M400 M410 M420
Position Mid Drive Motor Mid Drive Motor Mid Drive Motor Mid Drive Motor
Rated Power (W) 250 250 250 250
Max Torque (Nm) 80 80 80 80
Voltage (V) 36 / 48 36 / 43 / 48 36 / 43 / 48 36 / 43 / 48
Speed Limit (km/h) 25 / 32 25 25 25
Weight (kg) 3.8 3.9 3.3 3.6
Pedal Sensor Cadence Torque and Cadence Torque and Cadence Torque and Cadence
Throttle Option Optional No No No
Light Drive Capacity 6V / 3W (max) 6V / 3W (max) 6V / 3W (max) 6V / 3W (max)
Water Resistance IP X5 IP65 IP65 IP65
Certifications CE / EN 14764 / ROHS CE / EN 14764 / ROHS CE / EN 14764 / ROHS CE / EN 14764 / ROHS
Compatibility eMTB, Road & City Bikes Road & City Bikes eMTB & Cargo Bikes Road & City Bikes
Design Improvements Integrated Design, Advanced Sensors Weight reduction (3.3 kg) Enhanced integration for city and trekking e-bikes

Overcoming Challenges: Troubleshooting Bafang M400 Common Issues

Every e-bike motor has its quirks, and the M400 is no exception. But fear not! We’ve got you covered with solutions to common issues that might arise, ensuring your ride stays smooth and enjoyable.

Problem Description Troubleshooting Steps
Display and Battery Issues Issues with the battery display showing incorrect percentages can sometimes be attributed to compatibility issues between the battery and the display unit.
  • Verify compatibility between the battery and display unit.
  • Replace the display with a compatible one if issues persist.
Pedal Assist Sensor (PAS) Failures Problems with the PAS sensor can cause the pedal assist to not engage correctly, which could be due to sensor misalignment or internal wiring issues.
  • Check sensor alignment.
  • Inspect internal wiring for any disconnections or damage.
  • Open the motor to check the sensor if necessary, though this requires technical know-how.
Connection and Compatibility The M400 motor comes with either UART or CanBus communication protocols, affecting compatibility with various controllers and displays.
  • Ensure you have the correct setup and connectors for your motor’s communication protocol.
  • Match the communication protocol (UART or CanBus) with the compatible controllers and displays.

Hack Your Bafang M400: Tuning & Reprogramming

Rear view of the Bafang M400 motor showing the internal components and connectors

Tuning the Bafang M400 can significantly enhance its performance and adapt it to specific riding needs. However, the level of tuning and reprogramming you can perform depends on the communication protocol (UART or CanBus).

  1. Using Software and Cables: For motors with UART protocol, users can connect a programming cable and use software like the Bafang Config Tool to adjust settings. This includes modifying parameters such as start current, pedal assist levels, and throttle settings. Unfortunately, CanBus models are more restrictive and often require specialized tools or may not support extensive reprogramming.
  2. Modifying Pedal Assist and Throttle: Adjusting the PAS sensitivity and throttle response can tailor the motor’s output to the rider’s preference. While some users have successfully added throttles to their M400 setups, it’s generally not recommended due to potential legal restrictions and the risk of reducing the motor’s lifespan​.

Bafang M400 250W mid-drive motor

Bafang M400 250W


Installing Your Bafang M400 in a Few Simple Steps

  1. Preparation
    • Ensure all components are present: motor, battery, display, and necessary cables.
    • Fully charge the battery before installation.
  2. Mounting the Motor
    • Position the motor in the bottom bracket shell of the bike.
    • Secure the motor using the provided mounting hardware, ensuring all bolts are torqued to the manufacturer’s specifications to avoid loosening or damage.
  3. Installing the Battery
    • Slide the battery into its designated housing.
    • Secure it with the provided locking mechanism, using the key to lock it in place.
    • Ensure the battery is fully seated and locked to avoid electrical disconnections.
  4. Connecting the Display and Controls
    • Attach the display to the handlebars.
    • Connect the display to the motor using the appropriate cable, ensuring the connectors are fully engaged.
    • Mount the control unit within easy reach for convenient operation.
  5. Wiring and Connections
    • Route all wiring neatly, avoiding sharp bends and securing them with zip ties to prevent movement during rides.
    • Connect the pedal assist sensor and any optional components such as throttle or brake sensors.
  6. Final Checks
    • Verify all connections are secure and no cables are pinched or strained.
    • Turn on the system using the display unit, checking for any error codes.
    • Perform a test ride in a safe area to ensure all components function correctly.

Your E-Bike, Amplified: The Bafang M400 Experience

bafang m400 e bike conversion kit

The Bafang M400 Mid-Drive Motor is a true gem – a versatile companion that effortlessly blends power, efficiency, and personalization. Whether you’re weaving through city streets, tackling off-road trails, or conquering those daunting hills, the M400 has the potential to transform your riding experience. Thanks to its intuitive design, responsive performance, and the ability to fine-tune it to your unique style, the Bafang M400 truly empowers you to make the most of your e-bike adventures. So, whether you’re a seasoned e-biker or just starting your journey, consider the Bafang M400 your trusted partner on the path to electrifying your ride.

Pros Cons
Users frequently praise the motor’s smooth and responsive pedal assist, which makes riding more enjoyable and less strenuous. Some users have reported issues with the battery percentage display, which can sometimes show incorrect readings.
The motor’s robust construction and water resistance make it suitable for various weather conditions.  There have been occasional reports of pedal assist sensor (PAS) malfunctions, requiring adjustments or technical troubleshooting.
The battery options provide ample range for daily commutes and longer rides.

Leave a Comment

Your email address will not be published. Required fields are marked *