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Bafang motors explained: BBS kits, M series mid-drives and hub motors

How to read Bafang motor and display labels, what separates BBS kits, M series mid-drives and H series hubs, UART vs CAN, and why controller, display and motor must match.

Last edited Nov 9, 2026 by Pedalwise team Edit History Add a subpage

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Bafang makes mid-drive motors, hub motors, displays, sensors, controllers and batteries. Electric Bike Report calls it arguably the largest maker of e-bike hub motors, and lists Pedego, Juiced, Aventon and Charge among the brands that have used its motors (hub motor guide). Bafang parts also turn up in conversion kits. Unlike Bosch or Shimano, each bike maker picks its own mix of Bafang parts, so the details below matter when you replace one.

How to tell which one you have

  • Motor label. Bafang mid motors carry product codes starting with MM, for example the M510 is listed as MM G522.250.C (Bafang mid motors). Hub motors carry codes starting with RM, for example the H400B is listed as RM G020.250/350/500.D/DC (Bafang hub motors). The label on the housing is the one to trust, and Bafang's hub manual says not to remove it (RM G062 dealer manual).
  • Display name. Bafang display names start with DP. A display built for CAN bus says so in its name, such as the DP C271.CAN (DP C271 manual).
  • Kit listing. BBS kit sellers list the version. EM3ev, for example, sells its BBS02 kit in 36V and 48V versions and CANBUS versions, with a choice of displays (EM3ev BBS02 kit).

Models and what's different

  • M series mid-drives. Bafang lists more than twenty M models, from the M200 and M300 up through the M410, M420, M510, M560, M600, M620 and M820 (Bafang mid motors). Bike makers build these into their frames, so ask the bike brand for parts.
  • H series hubs. Bafang lists hub models from the H300 to the H730 (Bafang hub motors). Ratings vary a lot. The RM G062 dealer manual, for example, covers 48V versions rated 750 W and 1000 W, meant for fat bikes and all-terrain pedelecs off road (RM G062 dealer manual).
  • BBS kits. These bolt into a standard bottom bracket. EM3ev's BBS02 listing says it needs a 68 to 73 mm bottom bracket, has the controller built into the motor, and that a 36V kit must only be used with a 36V battery (EM3ev BBS02 kit). Keep any kit within the limits for your bike's class and local rules.

UART and CAN

Bafang parts talk to each other in one of two ways. UART is a simple direct link between two parts. CAN is a shared network that resists interference better and lets parts such as the battery share more detail. Bafang says it moved its products to CAN for reliability and easier expansion (Bafang on CAN and UART). The two work differently, so a CAN display and a UART controller are not a pair. Check the protocol, not just the plug, before you buy.

Why controller, display and motor must match

  • Ask the bike maker for the exact part. Ride1Up, for example, sells separate 500 Series controllers for its Bafang and Shengyi versions (Ride1Up 500 Series parts).
  • Matching affects how the motor runs. Bafang names poor matching of motor and controller as the main cause of electrical motor noise (Bafang FAQ).
  • Battery voltage must match. A kit's controller is set for one voltage (EM3ev BBS02 kit).
  • Codes depend on the display. Bafang's FAQ lists 04 as a throttle that has not returned to position, while the DP C271 manual uses 04 for a throttle fault and 05 for a throttle not returning (Bafang FAQ, DP C271 manual). Always use your own display's manual.

What this means for repair

What an owner can do:

What needs a shop:

  • Diagnosis and updates with BESST. Bafang says its BESST tool is needed for software updates and helps with diagnosis. Dealers get access through the bike brand (Bafang BESST).
  • Parts swaps. Controller, display, sensor and motor replacements, with the part matched to your bike.
  • Anything inside the motor. Bafang's hub manual says not to take the motor apart and to leave maintenance to authorized people with the right equipment (RM G062 dealer manual).

Pedalwise doesn't cover reprogramming a controller for more power or speed. Never open a motor, controller or battery. Battery and wiring faults need a pro. See battery won't charge and e-bike battery care.

Videos

Bafang M510: Boost Your Ride from Bafang E-Bike Drive Systems: The motor maker's own short introduction to its M510 mid-drive and where it fits in the range.

Related pages

Sources

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