48V 1000W rear hub kit mounted on a vintage Specialized Rockhopper Jr frame, using a CaliBike 48V 20ah battery pack. Sadly the frame triangle is fractions of an inch too small so I have to mount the battery on a rear rack. That said the bike is awesome. 30 MPH speed with over 30 miles of range. I plan to refit the whole set up to a bigger frame size this spring to better utilize the triangle battery set up.