You need a piece if straight steel (cut it long enough to go from the wheel lip to wheel lip), a vial from a level and a digital angle gauge (mine is for setting saw blade angles for my table saw).

Description: The 935DAG has a strong magnetic grooved surface to keep it in place on conduit, pipe, beams, and other ferromagnetic surfaces such as vents, ducts, and sawblades. It can be used to set ...