more nice price on Dhage,com for bafang motor. http://www.dhgate.com/product/48v-750w-8fun-bafang-mid-drive-central-motor/388530411.html#s1-13-1b;searl|137600874

48V 750W 8fun/Bafang Motor C965 LCD BBS02 Latest Controller Crank Motor Eletric Bicycles Trike Conversion DIY Ebike Kits

Spec:

1. Voltage: 48V  current Limit:25A

2. Power: 750W

3. Motor Weight: 4.8kgs
4. BB Length: 68mm 
5. Working Temperature of Dsplay: - 20- 80
6. Waterproof Grade: IP65

With an integrated speed sensor, this mid-drive motor, which is compatible with a 68mm bottom bracket, has a rated power of 750W, a reduction ratio of 1: 21.9 and a maximum torque of 160 N.m, will provide the rider with great explosive force when starting the system. Highly strong and efficient, this motor greatly enhances riding joy and is suitable for mountain bikes and sand bikes which are the favorites of riders who love challenges as well as transport bikes. This motor is black.