I used new knobby tires, 1.95 x 26 on front, 2.1 x 26 on rear. You can use used tires to save money. I used 8-32 nuts and Truss bolts because they have a larger head. Drill with 3/16 drill and drilled out a nut for a guide. Placed the guide between knobs and drill. I used 83 bolts per tire but you can use less. You need a rubber strip for between tube and bolts to protect the tube. Bolts were 3/16 long.