I’ll never forget the first time I twisted the throttle on a bike I’d built myself, powered by a Bafang BBSHD. The raw, instant torque felt like unleashing a small monster. It was exhilarating. Years later, I rode my first purpose-built eMTB with a Bafang M510 motor, and the feeling was completely different—it was like my own legs had become superhuman, seamlessly amplifying my every push.
These two experiences perfectly capture the soul of Bafang’s two distinct worlds. One is a universe of raw power, customization, and hands-on building. The other is a world of refined integration, intuitive feel, and factory polish. If you’re trying to navigate the Bafang landscape and decide which is right for you, you’ve come to the right place.
Key Difference: Bafang BBS vs. M-Series
The simplest way to think about it is:
BBS Series = DIY / Retrofit. These are kits you buy to convert a standard, non-electric bicycle into an e-bike.
M-Series = OEM / Integrated. These are motors sold directly to bicycle manufacturers to be designed and built into a purpose-built e-bike frame from the factory.
Here is a detailed comparison table:
| Feature | Bafang BBS Series (BBS01, BBS02, BBSHD) | Bafang M-Series (M400, M510, M620, etc.) |
| Intended Use | DIY Retrofit Kit. Designed to be installed by consumers or bike shops onto existing bicycles. | OEM Integrated Motor. Designed for bicycle brands to build a complete e-bike around the motor. |
| Installation | Fits into a standard threaded Bottom Bracket (BSA) shell. Relatively easy for a home mechanic. | Requires a proprietary frame mount. The bike frame must be specifically manufactured to fit the motor. |
| Sensor Type | Cadence Sensor. The motor provides power as soon as you start turning the pedals, regardless of how hard you push. | Primarily Torque Sensor. The motor measures your pedaling force and amplifies it. This feels more natural and intuitive. (Note: Some M-series, like the M400, use cadence/speed sensors). |
| Riding Feel | Powerful, raw, almost like a small motorcycle. The power feels “on/off.” A throttle is often used for fine control. | Smooth, intuitive, and natural. It feels like you have “super legs,” seamlessly amplifying your own effort. |
| Aesthetics | The motor hangs below the bottom bracket. It’s functional but looks like an add-on. | The motor is cleanly integrated into the bike’s frame, offering a sleek, professional look and better weight distribution. |
| Ecosystem | Open. You can mix and match displays, batteries, and throttles from various third-party suppliers. Highly programmable. | Closed. The motor, display, battery, and controller are designed as a single system using a specific communication protocol (usually CAN bus). |
| Serviceability | Easy for home mechanics to service and replace parts. A huge community and parts supply exist online. | More complex. Often requires specialized tools or dealer support. Parts can be harder to source for the average consumer. |
| Best For | E-bike enthusiasts who want to build a custom, powerful, and affordable e-bike and enjoy tinkering. | Riders who want a polished, reliable, and natural-feeling e-bike from a major brand and prefer a “just works” experience. |
Who Is This For? Real-World Scenarios
To make it even clearer, let’s look at who would choose each system:
The DIY Tinkerer (BBS-Series): Meet Dave. He has a 10-year-old hardtail mountain bike he loves. He’s on a budget, enjoys working with his hands, and wants the most power for the money to conquer the steep fire roads near his house. The BBSHD is Dave’s perfect motor. He gets immense power and the satisfaction of building his dream machine himself.
The ‘Buy and Ride’ Enthusiast (M-Series): Meet Sarah. She wants a reliable, sleek-looking eMTB for weekend trail riding. She values a natural ride feel, a factory warranty, and doesn’t want to worry about maintenance. She’s looking at bikes from brands like Frey, KBO, or other major manufacturers. An M510 or M600-powered bike is Sarah’s ideal choice. It’s a polished, purpose-built machine that just works.
Pros and Cons: The At-a-Glance Summary
Here’s a quick cheat sheet to help you decide.
| Bafang BBS Series (DIY) | Bafang M-Series (OEM) |
| PROS | PROS |
| ✅ Highly affordable power | ✅ Sleek, integrated look |
| ✅ Infinitely customizable/programmable | ✅ Natural, intuitive torque-sensing feel |
| ✅ Fits most standard bike frames | ✅ Factory warranty and dealer support |
| ✅ Huge community, easy to find parts | ✅ Optimized weight distribution and handling |
| CONS | CONS |
| ❌ Looks like an add-on | ❌ Significantly more expensive |
| ❌ Cadence sensor feels less natural | ❌ Locked ecosystem (motor, battery, display) |
| ❌ Can put stress on a non-e-bike frame | ❌ Requires a specific, proprietary frame |
| ❌ Requires DIY installation and know-how | ❌ Harder for a home mechanic to service |
The Complete List of Bafang Mid-Drive Motor Models in History
Here is a chronological and categorical breakdown of Bafang’s key mid-drive models.
Part 1: The BBS Series (The DIY Legends)
These are the motors that made Bafang a household name among e-bike builders. They are known for their power, simplicity, and reliability. The “B” in later models (e.g., BBS01B) signifies an updated controller.
BBS01 (and BBS01B)
Power: 250W / 350W
Voltage: 36V
History: The original. This was the first widely successful DIY mid-drive kit. The 250W version was designed to be street-legal in Europe and other regions with strict power limits. It proved that a reliable, affordable mid-drive was possible for the home builder.
BBS02 (and BBS02B)
Power: 500W / 750W
Voltage: 36V / 48V
History: This is the icon. The BBS02 hit the sweet spot of power, price, and reliability. The 750W, 48V version became the go-to choice for countless builds, offering fantastic performance for everything from commuting to moderate trail riding. It is arguably the most popular retrofit e-bike motor of all time.
BBSHD (also known as BBS03)
Power: 1000W (can be programmed for more)
Voltage: 48V / 52V
History: The “Heavy Duty” model. Bafang created the BBSHD to address the few weaknesses of the BBS02 when pushed to its limits. It features a much larger casing, robust metal internal gears (instead of one nylon gear), and better heat dissipation. It’s the king of high-power builds, perfect for off-road, cargo bikes, and speed demons.
Part 2: The M-Series (The OEM Contenders)
This series represents Bafang’s direct challenge to established OEM players like Bosch, Shimano, and Brose.
The Workhorses (City & Trekking)
M400 (G330): The most widely used M-series motor. It has 80Nm of torque and is a staple on countless city, trekking, and commuter e-bikes. Important Note: The M400 uses a speed/cadence sensor, not a torque sensor, so its ride feel is more like a very smooth and refined BBS motor. It’s known for being ultra-reliable and cost-effective.
M200 / M300: Lower-power, lower-torque versions of the M400, often found on entry-level or lightweight city bikes. They are prized for their quiet operation and reliability.
M410: A new, lightweight, and efficient 250W motor that is replacing the classic M400. It offers 80Nm of torque and is a significant update, offering a more modern package.
The eMTB Performance Motors (Torque Sensing)
M500 (G520): Bafang’s first true torque-sensing motor aimed at the eMTB market. With 250W and 95Nm of torque, it was a powerful and affordable alternative to Bosch’s Performance Line CX. It established Bafang as a serious OEM competitor.
M600 (G521): The more powerful brother of the M500. At 500W and 120Nm of torque, this motor is a beast, designed for high-performance eMTBs that aren’t restricted by the 250W street-legal limit. It’s powerful, torquey, and relatively lightweight for its output.
M510 (G522): The successor to the M500. This is a major leap forward. While it has the same “95Nm” torque rating, it’s completely redesigned. It’s lighter, delivers power more smoothly, has a more responsive torque sensor, and maintains power better at high cadences. It is considered a top-tier motor, competitive with the best from Bosch and Shimano.
M560: A new (2023+) high-power motor with a magnesium casing, rated at 500W and a massive 130Nm of torque, continuing the push into the high-performance eMTB space.
The “Ultra” Motor (The Top Predator)
M620 (G510 – The “Ultra”): This is a class of its own. The M620 is a monster of a motor, with a nominal rating of 1000W and 160Nm of torque. It uses a sophisticated dual-sensor system (both torque and cadence) for massive, yet controllable, power. It requires a special, wider bottom bracket and frame design. You will find the M620 on extreme performance fat bikes, high-end cargo bikes, and “ultra” e-bikes.
The Lightweight Motors (The New Frontier)
M820: A brand new (2023+) motor designed for the “lightweight” eMTB category. It’s incredibly small and light (2.3kg), with 75Nm of torque, designed to compete with motors from Fazua, TQ, and the Specialized SL systems. It’s all about providing a natural ride feel in a lightweight, agile package.
A Deeper Technical Dive for Enthusiasts
For those who want to geek out, the differences go even deeper.
Programmability (The BBS Advantage): The biggest superpower of the BBS series is its programmability. With a simple USB cable, you can connect your motor to a computer and tune everything—from the power percentage in each assist level to how aggressively the throttle responds. You can tame it for street use or unleash its full power for off-road.
Ecosystem: UART vs. CAN bus: The BBS series generally uses a UART protocol. Think of this as an open-source language. It allows you to mix and match displays, batteries, and throttles from dozens of vendors. The M-Series, like Bosch and Shimano, uses a CAN bus protocol. This is a closed, proprietary language. The motor, battery, and display are a locked set designed to work together perfectly, ensuring reliability but eliminating customization.
Real-World Reliability: The BBS series is famously robust, but not invincible. The nylon primary reduction gear in the BBS02 is a known weak point if you push it too hard. The BBSHD solved this with all-metal internals, making it nearly bulletproof. M-series motors are generally built to a very high standard of reliability, as they are backed by bike manufacturer warranties.
Conclusion: Are You the Chef or the Diner?
In the end, the choice isn’t about which motor is “better,” but which philosophy suits you.
Do you want to be the chef (BBS Series)? The person who hand-picks every ingredient, customizes the recipe, and builds a powerful, unique creation from the ground up. You accept the challenges of assembly and tuning for the ultimate reward of a bike that is truly yours.
Or do you want to be the diner at a fine restaurant (M-Series)? You trust the expert to design a perfectly balanced, refined, and reliable machine. You pay for the premium experience, the integrated design, and the peace of mind that it will perform flawlessly right out of the box.
Both paths lead to an incredible e-bike experience. The only question is how you want to get there.
Which Bafang world do you belong to? Let me know in the comments below!