A lawnmower motor ran bicycle with a budget of only $50.

Parts so far:
lawnmower which I got for free from some old lady with demencha
battery boxes that are two ammo boxes for $5 for each
bike frame that was old and used that must be modified so I can fit. $10 on a chuck of square aluminum tubing for the mod.
batterie regulator which came with the mower also charges it.

Sorry how crapy the 3D model is I very much rushed it.