The Tongsheng TSDZ8 represents the latest evolution of the Chinese brand’s mid-drive motors, fixing the TSDZ2 flaws while bringing more power. This 750W motor doesn’t just pack more muscle: it integrates a new clutch system, better cooling, and redesigned electronics. However, its larger size poses installation challenges not encountered with the TSDZ2B, particularly on frames with narrow chainstays.
TSDZ8: The Motor That Steps Up in Power and Requirements
The TSDZ8 isn’t simply a more powerful TSDZ2B. Tongsheng has revised the internal architecture to support 750W continuously without overheating, but this evolution comes with stricter installation constraints. The motor measures several millimeters more in diameter, which can create interference with certain frames.
TSDZ8 vs TSDZ2B Technical Features
| Feature | TSDZ8 | TSDZ2B (Comparison) |
|---|---|---|
| Nominal power | 750W only | 350W or 500W |
| Maximum torque | 120 Nm (up to 140 Nm peak) | 80 Nm maximum |
| Motor diameter | 5mm wider | Standard compact |
| Frame compatibility | Chainstays > 75mm required | Fits most frames |
| Carbon frames | Incompatible (vibrations) | Compatible with precautions |
| Display connector | 8 pins (new standard) | Standard connector |
| Approximate price | $650-850 with battery | $400-500 with battery |
Critical Point: The TSDZ8 generates more vibrations than its little brother due to its power. Manufacturers formally advise against installation on carbon frames to avoid micro-cracks. Also check available space around the bottom bracket.
Pre-Installation Checks: Avoid Unpleasant Surprises
TSDZ8 installation fails more often than TSDZ2B due to physical compatibility problems. Several users discovered after purchase that their frame didn’t allow installation. This preliminary check will save you from costly disappointment.
Frame Compatibility Checklist
| Element to Check | Required Dimension | How to Measure |
|---|---|---|
| Bottom bracket width | BSA 68-73mm exclusively | Calipers on threaded shell |
| Chainstay clearance | Minimum 75mm each side | Ruler from BB axis to chainstay |
| Frame height | Ground clearance > 30cm | From ground to center of bottom bracket |
| Frame material | Steel or aluminum only | Visual check/label verification |
| Brake type | No coaster brake | Visual check of rear hub |
TSDZ8 Specific Tools
- Special M33.5 wrench: Supplied with kit, different from TSDZ2B M33
- Spacing shims: Often needed to prevent contact with chainstays
- Chainring adapter: May be required to optimize chainline
- 50 Nm torque wrench: Higher torque values than TSDZ2B
Step-by-Step Installation: Managing the TSDZ8’s Imposing Size
TSDZ8 installation generally follows the same logic as other Tongsheng motors, but its larger size demands more attention to detail. Critical steps concern motor positioning to avoid contact, and chainline management which can be disrupted by the larger diameter.
Phase 1: Dismantling & Frame Inspection
Bike Preparation
- Complete crankset dismantling: Pedals, cranks, existing bottom bracket
- Thorough cleaning: Bottom bracket threads without grease residue
- Dry test: Present motor without tightening to check clearance
- Clearance measurement: Motor/chainstay distance with metal ruler
TSDZ8 Specific Watch Points
- Right chainstay contact: Most critical area, check entire circumference
- Chain routing: Wider motor may interfere with alignment
- Electrical cable: Cable exit positioned correctly
Phase 2: TSDZ8 Motor Installation
Positioning and Mounting
- Right side insertion: Push motor until stop in bottom bracket
- Add shims if necessary: 5mm spacers to prevent chainstay contact
- M33.5 nut tightening: 45 Nm torque, higher than TSDZ2B
- Check for play: Motor must not move
Anti-Rotation Management
- Traditional bracket removal: TSDZ8 no longer uses chainstay plate
- Friction locking: Tighter M33.5 nut ensures retention
- Thread locker addition: Recommended to secure assembly
Phase 3: Chainring & Drivetrain Installation
Chainline Optimization
- Standard 44T chainring: Supplied with offset for compensation
- Alignment test: Chain should run straight in 4th gear
- BCD adapter if needed: Solution for problematic frames
- Ground clearance check: Chainring must not touch
Crank Mounting
- TSDZ8 170mm cranks: Motor-specific, more robust
- 50 Nm tightening: Higher torque than TSDZ2B
- Thread locker application: Prevents loosening in intensive use
- Final check: Free rotation without hard spots
Phase 4: Electronics & 8-Pin Connector
New Feature: 8-Pin Connector
- Old display incompatibility: VLCD5/6 require adapter
- Recommended displays: 860C color or SW102 Syklo
- Reinforced wiring: More functions transmitted to display
- Critical waterproofing: 8-pin connection more sensitive to moisture
Speed Sensor Installation
- New pick-up design: More precise but more sensitive to alignment
- Left chainstay mounting: Metal bracket provided
- Precise 3-5mm adjustment: Critical gap for proper function
- Wheel rotation test: Real-time speed display verification
TSDZ8 Specific Configuration and Settings
The TSDZ8 integrates updated firmware that fixes defects from early versions, notably the assistance problems of the first two levels and walk assist. These improvements require initial configuration different from the TSDZ2B.
860C Display Advanced Menu
Advanced Configuration Access
- Access code: 1919 to unlock technical menu
- Power setting per level: Fine assistance customization
- Torque sensor parameters: Sensitivity adaptable to pedaling style
- Temperature limits: Configurable overheating protection
Optimal Settings by Usage
| Usage Profile | Torque Setting | Power Limitation | Comment |
|---|---|---|---|
| Urban commuting | Low sensitivity | 400W max | Preserves range |
| Mixed touring | Medium sensitivity | 600W max | Performance/range balance |
| Mountain biking | High sensitivity | 750W max | Maximum performance |
TSDZ8 Specific Problems and Solutions
The TSDZ8 presents different failures from the TSDZ2B due to its higher power and more recent design. User feedback reveals specific weak points that must be known to anticipate problems and optimize reliability.
Known Failures and Prevention
| Problem | Cause | Solution | Prevention |
|---|---|---|---|
| Chainring/chainstay contact | Insufficient frame clearance | BCD adapter + smaller chainring | Measure before purchase |
| Controller overheating | Intensive 750W use | Climbing breaks, ventilation | Limit power to 600W |
| 8-pin connector failure | Moisture infiltration | Cleaning + dielectric grease | Waterproof connection protection |
| New clutch noise | Clutch system break-in | Normal, decreases with use | 200 km break-in period |
| M33.5 nut loosening | Strong 750W vibrations | Thread locker + re-tighten 50 Nm | Check tightening at 100 km |
TSDZ8 Specific Maintenance
- Monthly tightening check: Stronger vibrations require monitoring
- 8-pin connector cleaning: More sensitive than standard connectors
- Temperature monitoring: Avoid intensive use in hot weather
- Clutch lubrication: Every 1000 km for clutch system
TSDZ8 vs Competition: Realistic Positioning
The TSDZ8 positions itself between entry-level motors like the TSDZ2B and high-end systems like Bosch or Shimano. This intermediate position brings advantages but also compromises that must be known to make an informed choice.
Objective Comparison with Alternatives
| Criteria | TSDZ8 | Bafang BBSHD | Bosch CX |
|---|---|---|---|
| Natural assistance | Excellent (torque sensor) | Good (cadence sensor) | Excellent (torque sensor) |
| Raw power | Good (750W) | Excellent (1000W+) | Limited (250W legal) |
| Reliability | Good (new product) | Very good (proven) | Excellent (industrial) |
| Price with battery | $650-850 | $700-900 | $1700+ (OEM only) |
| Installation ease | Difficult (space constraints) | Moderate | Impossible (complete e-bike) |
Verdict: The TSDZ8 suits users seeking more power than the TSDZ2B without BBSHD installation constraints, accepting in return reliability yet to be proven in the long term.
TSDZ8 Operational: Power to Tame
Your TSDZ8 transforms your bike into a machine capable of tackling the steepest gradients with 750W of power and 120 Nm of torque. This power demands respect: monitor temperatures, regularly check tightening, and adapt your riding to this new level of performance.
The TSDZ8 offers the best compromise between power, natural assistance and price. Respect its thermal limits and installation requirements, it will offer unmatched sensations on all terrains.
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