Planned parts:

• Motor: Brushless DC 24V/250W - Hub motor with planetary gear - mounted in 16" rim
• Controller: SBC V2
• Battery: Lead-Acid 12V/12Ah - Use two pieces, total 24V/12Ah
• Charger: LT1074HVCT - Step-Down switching regulator
• Panel: Kaneka Hybrid PV 135W (59V/2.2A)

Current status: 

Because the company where I worked was closed (factory for assembling PV panels).
So I had to terminate this project :(

update 1 (22.06.2011)

• Because motor have a freewheel, and reverse rotation cannot be possible, then we must remove it.
• Completed charger, used LT1074HVCT connected as buck converter. With output 27,5V

Buck converter circuit (charger):

typical application, R4 is used for fine tunning. more info in datasheet

Main control box (unfinished, without SBC):

Top center: LCD info panel + logic

Bottom left: Battery charging unit

Bottom right: current measuring unit

Bottom: some switches and connectors for battery, panel, motor, sensors, etc...