is there any place in or near lusaka that rents motorbikes?
zambia motorbike rentals
Try a simple Google type search with your computer.
Sample quick search:
Up to you to investigate any special insurance or license requirements to legally ride in Zambia. Also, an accident with a motorbike might not be covered by your medical insurance.
Your particular embassy or consulate may have information for driving in Zambia.
Good luck.