Finished installing a 750-watt Tongsheng mid drive on Terry C's 559 last night. Obtained the drive kit from ECO Cycles (Their product TDSZ-TOO). Configured the display this afternoon, then took the trike on a successful 2.3-mile test ride on the Santa Fe Trail. Fabricated the display T-mount from carbon fiber tubing and turned the aluminum handlebar-to-T-mount adapter on my lathe. The motor kit, battery, and T-Cycle battery mounting assembly cost $1,580 compared to $2,850 for a 250-watt e-Cat Bosch kit.
 
 
 
 
                                                                                                                                                                                   750-watt Tongsheng drive. Slipped into bottom bracket receiver shell and secured with ring nut.
 
 
 
 
52v 20ah Hailong battery.                                                                                                                                               Bafang 860c color display flashed with open source firmware. Pushbutton control unit and throttle are to the left of the display.
 
 

Thanks Diana. We have two holdouts. One says he'll go E someday, while the other says "never".