Phoenix II Power System - Rear Motor with 7-speed Freewheel - Phoenix Brute - 4840 Controller - 29 inch - Thumb Throttle - APM Display Phoenix II bike kits are extremely reliable, with over 50,000 miles on older systems still in use For the serious commuter. Fast, powerful, green. No more gasoline Phoenix 3640 is 1440 Watts, 4840 is 1920 Watts, and 7240 is 2880 Watts ElectricRider Service Center has parts in stock