BBSXX Electric Bike Motor

One of the most popular electric bicycle conversion motors, the Bafang bbs02 is a 750 watt mid-drive motor and the Bafang bbsHD is a 1000 watt mid-drive motor. They are similar in design and are commonly referred to interchangeably as a BBSXX.


Notes while installing one of my bbs02 units

What you need:

  • Pedal removal wrench
  • A bafang install tool
  • crank arm puller tool
  • Long wrench. You can never have too much leverage.
  • Grease
  • Medium-grade thread locker
  • A set of 1-10mm hex bolt drivers/wrenches
  • Paper Towels


  • Remove the old bottom bracket
    • Remove the pedals
    • Remove the crank arms (you will want as long a wrench as possible for doing this)
    • Remove the old bottom bracket (Again, a long wrench is a lifesaver, just for the extra torque you can apply on this)
      • Remember to remove the non-drive side part first (loosens counter-clockwise - left turn)
      • Remember that the drive-side part is reversed (loosens clockwise - right turn)
  • Install the motor
    • grease the inside of the bottom bracket shell (on the bike frame)
    • Insert the motor into the bottom bracket shell.
    • Install the lock ring mechanism. Use one of the “bafang install tools” you can find easily by googling. This is also one of the places you want to at least be close to the appropriate torque rating.
    • At this point, the drive unit should be securely installed and shouldn’t move at all as you try to push down on it.
    • Install the chain ring
    • Install the cranks
    • Install the pedals onto the crank arms
  • Install the extra cabling.


Notes I took while uninstalling one of my bbs02 units to move it to a different bike.

What you need:

  • Pedal removal wrench. The longer the wrench, the better (more torque!)

  • Grease

  • Medium-grade thread locker

  • Spline tool

  • Spanner wrench

  • Crank arm puller

  • A set of 1-10mm hex bolt drivers/wrenches.

  • Paper Towels

  • Remove the pedals (Using the pedal wrench)

  • Once the pedals are removed, remove the crank arms. Clean off the existing grease and set aside.

  • Remove the chainring. This uses 4mm hex bolts.

  • Remove the lock ring mechanism. This is the top splined nut, y-shaped thing, the lock-ring, and the washer underneath the lock-ring. Remove the nut using a spline tool, use a 5mm bolt driver to remove the bolts on the 5-shaped nut, and use a spanner to remove the lock-ring. The washer will come off. Set aside all of these close to each other.

  • At this point, the drive unit will slide out of the bottom bracket of the bicycle. Be sure to unplug all the cables that are connected to it first, of course.

  • Remove the cables remaining on the bicycle.

Last updated: 2022-08-14 18:29:20 -0700