Bafang BBSHD Installation Guide UK: Complete Step-by-Step Walkthrough

Use a crank puller matched to your crank type. Loosen the crank bolt first, thread the puller body into the crank, then advance the centre spindle until the crank pops free. Do both sides.

On a BSA shell: the right-side cup is left-hand thread (loosens clockwise); the left-side cup is right-hand thread (loosens anticlockwise). Apply penetrating oil and wait 20 minutes if the BB has been in place for years.

Wire-brush or clean all thread surfaces. Inspect carefully for damaged or stripped threads — the motor’s M33 lock rings need clean threads to torque properly.

Apply a thin, even coat of anti-seize compound to the internal shell threads. This prevents galvanic corrosion and ensures the motor can be removed in future.

Lower the motor sleeve into the BB shell from the right. It should slide in with light resistance. Before seating fully, rotate the motor to plan the harness connector port position — ideally pointing upward for clean cable routing.

Thread it finger-tight, then fit the M33 4-notch socket and torque wrench and tighten to 50 Nm. This is the single most critical fastener on the entire installation.

Use the 16-notch socket. Torque to 25 Nm — lower than the inner because it is aluminium and will strip if over-tightened.

Final-tighten the retaining bracket bolts to 10 Nm. Hold the bracket pressed upward against the shell edge while tightening.

Mount the chainring on the spider with Loctite 243 on the bolt threads. Torque chainring bolts to 6–8 Nm. Check chainline: the chainring centre should align within 2mm of the centre of the cassette’s middle sprocket.

Slide each crank arm fully onto the splined output shaft. Insert the crank bolt and tighten to 12–15 Nm with a 6mm hex key.

Route upward along the down tube toward the bars. Use cable ties at 20–30cm intervals. Never route cables near the chain path.

When the lever is squeezed, motor power cuts immediately. Do not omit brake sensors — they are a safety system, not optional.

The display connector is a keyed waterproof circular plug. Match the guide pin and push until it clicks. Do not force — keyed connectors only seat in one orientation.

The gap between sensor face and disc must be 1–3mm. Too large and pedal assist response will be sluggish. Too small and the disc will contact the sensor.

Clip the magnet to any rear wheel spoke. Mount the sensor body on the chainstay so the magnet passes within 3–5mm of the sensor face during wheel rotation.

Tighten the collar bolt to 1 Nm — just enough to hold position. Do not overtighten; the collar threads are fine and strip easily.

The BBSHD runs on 48V or 52V. Do not connect a 36V battery. Minimum recommended capacity: 17.5Ah (840Wh+). Browse our battery range.

With the motor running in PAS mode, squeeze each brake lever. Power must cut immediately. Do not ride the bike until brake cut-offs are confirmed working on both levers.