| Model number | GDR-21 | ||
| Position | Rear | ||
| Construction | Gear | ||
| Rated voltage(V) | 24/36/48 | ||
| Rated Power(W) | 180-350 | ||
| Weight(kg) | 2.8 | ||
| Reduction Ratio | 1:8.5 | ||
| Wheel Diameter(inch) | 16-28 | ||
| Rated speed(km/h) | 20-30 | ||
| Magnet Poles(2P) | 10 | ||
| Dropout(mm) | 135 | ||
| Brake Type | V/Disk brake | ||
| Freewheel | 6-7S | ||
| Operating Temperature © | -20---45 | ||
| Efficiency(%) | ≧78% | ||
| Color | Black | ||
| Cabling Route | Shaft center right | ||
| Noise Grade(dB) | ≤60 | ||
| IP Grade | IP54 | ||
| Salt Spary Test Standard(h) | 24/96 | ||
| Magnetic Steel(H) | 17 | ||
