Knuckle or Bracket System… Which is right for you? For most people, the primary considerations are track width, lift height and tire size. Track width is the measurement from outside of tire-tooutside of tire. As with all brands of HD replacement knuckle style lifts, track width must be increased to gain wheelto-knuckle clearance. Our Bracket style lift does not alter track width. Both systems include all necessary components and were designed with Superlift’s legendary attention to detail.