If you're on team Ryobi, you probably already have a few batteries and chargers already, and if you don't we recommend the 4.0 Ah batteries for their great combination of longevity and weight.
The bike conversion is relatively conventional with the crank replaced by a crank and motor assembly, and a pair of the Ryobi packs in 3D-printed holders on the frame. The value in this is in its ...