System Overview
This section provides an overview of the BAFANG BBS01/BBS02 mid-drive motor system for electric bicycles.
Image Description: A bicycle with a mid-drive motor installed. Arrows point to the display unit on the handlebars, the speed sensor on the rear wheel, and the speed sensor magnet on the rear wheel spokes.
Image Description: Close-up views of the BAFANG BBS01/BBS02 mid-drive motor unit, showing its compact design and integrated components.
Technical Parameters for 250W, 36V Motor
| Parameter | Value |
|---|---|
| Voltage | DC36V |
| Limit current | 15A |
| Limit speed | 25KM/H |
| Motor weight | 3.7KG |
| Chain wheel tooth | 46T |
| current (A) | no-load value | Rated value | Max value | |||||
|---|---|---|---|---|---|---|---|---|
| speed (RPM) | Output power (W) | speed (RPM) | efficiency (%) | torque (N m) | current (A) | MAX torque (N.m) | MAX efficiency (%) | |
| ≤1.0 | 83±5 | 250 | 78±5 | ≥80% | ≥30 | ≤9 | ≥80N.m | ≥80% |
Diagram Description: Technical drawing of the BAFANG motor unit showing dimensions and component placement. Key dimensions include 210mm for the chainring diameter and various mounting points.
Diagram Description: Detailed technical drawings of the BAFANG motor unit, including side and front views with precise measurements for installation, such as 117.5mm and 199.25mm dimensions, and mounting hole specifications like 2-M8x1.
Installation Procedures
Follow these steps carefully to install the BAFANG BBS01/BBS02 conversion kit.
- Package Contents Check: Open the package and take out the drive unit and accessories. Verify that the motor specifications are correct and all accessories and wiring are included as per the packing list.
- Chain Wheel and Cover Installation: Fix the chain wheel onto the drive unit using 5x M5*10 screws. Then, attach the chain cover (optional) to the chain wheel using 5x ST3.9 screws. Do not use Loctite with these bolts.
Image Description: Close-up of the chain wheel being attached to the drive unit with M5x10mm screws. Labels indicate "Recessed Surface" and "Higher Surface" for proper alignment.
- Drive Unit Axle Installation: Carefully feed the drive unit axle through the bicycle's bottom bracket. If resistance is encountered, the BB shell may require smoothing of burs or weld overflow with a rounded file.
Image Description: The drive unit being inserted into the bicycle's bottom bracket. The image shows the axle passing through the frame.
- Axle Thread Check: Ensure the thread of the axle tube extends beyond the bottom bracket by more than 10mm. Note that for 73mm bottom brackets, this measurement may be less.
Image Description: Close-up of the bicycle frame's bottom bracket area, showing the axle thread extending outwards.
- Fixing Plate Installation: With the teeth on the fixing plate facing inwards, secure the plate to the drive unit using 2x M6 x 10mm bolts. Loctite can be used if desired.
Image Description: Two diagrams illustrating the fixing plate. One shows the plate with teeth, labeled "Fixing Plate Teeth (Outside when fitted)". The other shows the plate from the outside, labeled "Fixing Plate (Outside Surface Without Teeth)". Two M6 bolts are also shown.
- Drive Unit and Nut Tightening: Hold the drive unit against the frame and simultaneously tighten the M6 x 10mm bolts and the M33 nut. Tighten the M33 nut to a torque of 30-40Nm. Use the BBB Lockring tool if you have the installation toolkit.
Image Description: A person tightening the M33 nut on the drive unit using a tool. An arrow points to the "M33 Nut".
- BB Cup Fitting: Once the previous step is tightened, fit the BB cup over the M33 nut. Tighten to 20-30Nm.
Image Description: A close-up of the BB cup and a tool used for its installation.
- Left Hand (LH) Crank Installation: Fix the LH crank onto the bike using the M8 inner hex bolt. Tighten with a force of 35-40Nm. Loctite is recommended as this bolt is prone to loosening.
Image Description: The left crank arm being attached to the drive unit. An arrow points to the "LH Crank", and another to the "M8 Nut".
- Right Hand (RH) Crank Installation: Fix the RH crank onto the bike using the M8 inner hex bolt. Tighten with a force of 35-40Nm. Loctite is recommended as this bolt is prone to loosening.
Image Description: The right crank arm being attached to the drive unit. An arrow points to the "RH Crank", and another to the "M8 Nut".
Note: It is crucial not to confuse the left and right cranks, as doing so can lead to malfunction or serious damage.
- Wiring Harness Connection: Connect the waterproof harness, Anderson connectors for the battery, and the speed sensor to the motor unit.
Image Description: The waterproof wiring harness connected to the motor unit.
Image Description: Anderson battery connectors being attached. A note indicates that user-provided connectors are acceptable if they have a similar current rating of 40a.
- Speed Sensor Mounting: Mount the speed sensor and magnet. The optimal position for the magnet is less than 5mm from the sensor on the rear wheel.
Image Description: Multiple images showing different views and methods for mounting the speed sensor and magnet on the bicycle's rear wheel. One diagram provides specific dimensions for the sensor (44.75mm length, 12.5mm width).
Component Connection Diagram
This diagram illustrates how the various components connect to the main harness.
Diagram Description: A schematic showing the electrical connections. Components are labeled A through H, K, and L. The diagram shows connectors for brake cutoff/magnetic sensors (A), display (B), throttle (C), main harness (D), battery connectors (E), battery to controller (F), speed sensor (H), gearsensor (K), and light (L).
- A – Brake Cutoff / Magnetic Sensor Plugs (2) – Yellow – Female At Harness
- B – C961 Display – Green – Male at Harness
- C – Throttle – Yellow – Male at Harness
- D – Main Harness waterproof connection
- E – Battery Connectors
- F – Battery G – Controller
- H – Speed Detecting Sensor
- K - connector for gearsensor (where applicable)
- L - connector for light 6V (where applicable)
Display, Throttle, and Control Location
The image below shows a common setup for the display, throttle, and On/Off & PAS controls on the handlebars. Installation may require removing grips and other components.
Image Description: A bicycle handlebar setup showing the throttle on the left side, and the BAFANG C961 display and On/Off, PAS Control buttons on the right side.
Packing List
- BBS01 / 02 Motor
- Display
- Brakes / Cutoff Sensor (2 pieces)
- EB-BUS Cable
- Fixing Plate (with teeth)
- Chain Wheel and Chain Wheel Cover
- Cranks (2 pieces)
- M5 x 10mm Nut (5 pieces)
- M6 x 12mm Nut (2 pieces)
- M33 Nut And Cup (2 Pieces)
- ST 3.7 Nut (2 Pieces)
- Speed Detection Sensor
- Speed Detection Magnet
Warranty
The general warranty does not cover or apply to the following:
- Damage, failure and/or loss caused by refitting, neglect, improper maintenance, competition or commercial purpose, misuse, abuse or accident.
- Damage, failure and/or loss caused by shipping.
- Damage, failure and/or loss caused by improper installation, adjusting or repairing.
- Damage, failure and/or loss irrelevant to material and workmanship, e.g., failure to follow instructions by consumers.
- Damage, failure and/or loss caused by product's appearance and surface change which doesn't affect its function.
- Damage, failure and/or loss caused by unauthorized service or installation.
- Damage, failure or loss caused by normal wear and tear.
- Re-programming the controller will void any warranty.
