Hi everyone,
I’m seeking technical insight into a progressive failure of my TSDZ2B (48V system, 860C display, 960Wh battery, Batch tf2025h).
Phase 1: Initial symptoms (The first 50 km)
From the very first ride, the bike felt unusually heavy to pedal without assistance. I configured the display for 3 assist levels and used only Level 1. Despite the light assist and the large 960Wh battery, I only got about 50 km before the battery died very unexpectedly (likely a sudden voltage sag under load).
Phase 2: Total failure
The unit has now failed completely:
Manual test: With the drivetrain removed and phase wires separated, the bare motor core is extremely stiff to turn by hand and makes a grinding noise.
Power test: Under throttle, the motor barely rotates, struggles, and gets very hot almost instantly.
Two Theories – What happened?
Mechanical Drag in Housing: Could a manufacturing defect or misalignment in the main housing/shaft bearings have created enough constant friction to make unassisted pedaling heavy and eventually overload the motor to the point of seizure?
Defective Motor Core (The "Lemon"): Alternatively, could this be caused purely by a faulty motor core from the factory? If the motor had internal mechanical interference or a shorted winding from day one, would that explain the heavy pedaling feel and the extreme energy consumption even on Level 1?
Questions for the community:
Has anyone experienced this level of resistance "out of the box" with the 2025 "tf" batches?
Given the symptoms, does this sound like a housing/bearing issue that killed the motor, or just a DOA motor core?
With a 960Wh battery, 50 km on Level 1 is approx. 19.2 Wh/km. How much of that was likely lost to internal heat/friction?
I’ve attached a video of the seized motor core. Any insights would be much appreciated!
Link to video
I’m seeking technical insight into a progressive failure of my TSDZ2B (48V system, 860C display, 960Wh battery, Batch tf2025h).
Phase 1: Initial symptoms (The first 50 km)
From the very first ride, the bike felt unusually heavy to pedal without assistance. I configured the display for 3 assist levels and used only Level 1. Despite the light assist and the large 960Wh battery, I only got about 50 km before the battery died very unexpectedly (likely a sudden voltage sag under load).
Phase 2: Total failure
The unit has now failed completely:
Manual test: With the drivetrain removed and phase wires separated, the bare motor core is extremely stiff to turn by hand and makes a grinding noise.
Power test: Under throttle, the motor barely rotates, struggles, and gets very hot almost instantly.
Two Theories – What happened?
Mechanical Drag in Housing: Could a manufacturing defect or misalignment in the main housing/shaft bearings have created enough constant friction to make unassisted pedaling heavy and eventually overload the motor to the point of seizure?
Defective Motor Core (The "Lemon"): Alternatively, could this be caused purely by a faulty motor core from the factory? If the motor had internal mechanical interference or a shorted winding from day one, would that explain the heavy pedaling feel and the extreme energy consumption even on Level 1?
Questions for the community:
Has anyone experienced this level of resistance "out of the box" with the 2025 "tf" batches?
Given the symptoms, does this sound like a housing/bearing issue that killed the motor, or just a DOA motor core?
With a 960Wh battery, 50 km on Level 1 is approx. 19.2 Wh/km. How much of that was likely lost to internal heat/friction?
I’ve attached a video of the seized motor core. Any insights would be much appreciated!
Link to video
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