Product Features:
MY1016Z3 350W 36V  Brush Motor
No-Load Speed : 3850rpm
Rated speed: 3200rpm 
Gear Ratio: 9.78:1 
Weight: 2.94 kg 
Sprocket: 9 teeth sprocket 410 (use for ordinary bicycle chain)

Pitch: 12.7mm (1/8")
Tooth thickness: 3mm
Inside diameter: 11mm
Outside diameter: 41mm                                  
Rated Current      : 12.5 A    
No-Load Current :  2.0A