Danger: High Voltage & Safety
Ensure the motor is unplugged from the battery pack during installation to avoid accidental throttle engagement or electrical short circuits.
Required Parts & Tools
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Replacement Parts Needed
- Tongsheng TSDZ2 36V/48V Motor Kit$250 - $350
Complete TSDZ2 mid-drive motor kit with display, wiring harness, speed sensor, and crank arms.
- 36V or 48V E-Bike Battery Pack$180 - $300
Matching voltage lithium-ion battery with a high-current discharge port.
Tools Required
- Standard bottom bracket tool$10 - $15
Used to remove the existing square-taper or cartridge bottom bracket cups from the bicycle frame.
- TSDZ2 lockring tool$8 - $12
A specialized 44mm locknut spanner required to tighten the motor axle lockring on the non-drive side.
- Crank puller tool$6 - $10
Necessary for pulling the existing crank arms off the bottom bracket spindle.
DIYStep-by-Step Instructions
- Step 1 of 5
Remove the Bottom Bracket & Cranks
First, remove the pedals, crank arms, and then extract the existing bottom bracket cartridge from the frame using a splined bottom bracket tool. Thoroughly clean the inside of the bottom bracket shell to remove dirt, grease, and rust.
- Step 2 of 5
Insert the TSDZ2 Spindle
Gently push the motor's main spindle through the bottom bracket shell from the drive-side (right side) of the bicycle. The motor housing should rest flat against the bottom bracket shell face. Ensure no cables are pinched between the frame and the motor.
- Step 3 of 5
Install the Fixing Plate & Lockrings
On the non-drive side, slide the steel mounting fixing plate onto the spindle. Secure it to the motor housing using the provided bolts. Thread the main lockring onto the spindle and tighten it securely using the specialized TSDZ2 lockring wrench, then install the secondary lockring.
- Step 4 of 5
Secure the Anti-Rotation Bracket
Fit the anti-rotation support block between the motor body and the bicycle chainstays. Tighten the retaining bolt so the bracket presses firmly against the frame, preventing the motor from rotating forward under high pedal torque.
- Step 5 of 5
Connect Sensors & Electronics
Mount the speed sensor on the rear chainstay and align the wheel spoke magnet. Run the wiring harness up the frame, mounting the display on the handlebars. Connect the waterproof color-coded plugs: blue for the display, yellow for the speed sensor, and the thick power leads to the battery mount.
Understanding Torque-Sensing Mid-Drives
Unlike simple cadence-based motor kits (such as the Bafang BBS02) which only detect if the pedals are spinning, the Tongsheng TSDZ2 features a built-in torque sensor. It measures how hard you are pedal-pushing and amplifies your effort instantly. This makes the ride feel natural and organic, like you have super-powered legs, rather than being pulled by a throttle.
Bicycle Compatibility Requirements
Before starting, check your bicycle specifications. The TSDZ2 fits standard BSA threaded bottom brackets with a width of 68mm to 73mm, and an internal diameter of roughly 33.7mm. If you have a press-fit bottom bracket or a fat-bike, you will need specialized adapters or a specific wider axle model.